function mostrarCalendario(calTXT)
{
  obj = MM_findObj("calDiv");
  obj.innerHTML = calTXT;
  MM_showHideLayers('calDiv','','show');
  MM_dragLayer('calDiv','',0,0,0,0,true,false,-1,-1,-1,-1,-1,-1,50,'',false,'')
}

function ocultarCalendario()
{
  MM_showHideLayers('calDiv','','hide');
}

function diaSeleccionado(dia, mes, ano, item, formato)
{
  var valor = construirFecha(dia, mes, ano, formato)
  obj = MM_findObj(item);
  obj.value = valor;
  ocultarCalendario();
}

function obtenerUltimoDia( ano, mes)
{
  if ( mes == 0 || mes == 2 || mes == 4 || mes == 6 || mes == 7 || mes == 9 || mes == 11 )
  {
    return 31;
  }
  else if ( mes == 3 || mes == 5 || mes == 8 || mes == 10 )
  {
    return 30;
  }
  else
  {
    if ( (ano % 4) == 0 && (ano % 400) == 0 )
    {
      return 29;
    }
    else
    {
      return 28;
    }
  }
}

function calcularMesAno( mes, ano, incr)
{
   var ret_arr = new Array();
   if (incr == -1) {
      if (mes == 0) {
         ret_arr[0] = 11;
         ret_arr[1] = ano - 1;
      }
      else {
         ret_arr[0] = mes - 1;
         ret_arr[1] = ano;
      }
   } else if (incr == 1) {
      if (mes == 11) {
         ret_arr[0] = 0;
         ret_arr[1] = ano + 1;
      }
      else {
         ret_arr[0] = mes + 1;
         ret_arr[1] = ano;
      }
   }
   return ret_arr;
}

function imprimirEncabezado( mes, ano, item, formato)
{
  var diaSemana = new Array("Do", "Lu", "Ma", "Mi", "Ju", "Vi", "Sa");
  var meses = new Array("Enero", "Febrero", "Marzo", "Abril", "Mayo", "Junio", "Julio", "Agosto", "Setiembre", "Octubre", "Noviembre", "Diciembre");
  var aPrev = calcularMesAno( mes, ano, -1);
  var aNext = calcularMesAno( mes, ano, 1);
  var vTxt = "";
  vTxt = "<table class='tablaCalendario'>";
  vTxt += "<tr class='filaMes'>";
  vTxt += "<td colspan=6 class='titulo'>Seleccione una fecha</td>";
  vTxt += "<td colspan=1 class='titulo'>";
  vTxt += "<a style='color:white; text-decoration:none; font-height:bold;' href='javascript:ocultarCalendario();'";
  vTxt += "onMouseOver='window.status=\"Ocultar calendario\"; return true;' onMouseOut='window.status=\"\"; return true;'"
  vTxt += "> x </a></td></tr>";
  vTxt += "<tr class='filaMes'>";
  vTxt += "<td class='mes' colspan=7>";
  vTxt += " <a href='javascript:construirCalendario("+ mes + ", " + (ano - 1) + ", \"" + item + "\", \"" + formato + "\")' ";
  vTxt += "onMouseOver='window.status=\"A?o anterior\"; return true;' onMouseOut='window.status=\"\"; return true;'";
  vTxt += "> << </a> &nbsp;&nbsp;";
  vTxt += " &nbsp;&nbsp;<a href='javascript:construirCalendario("+ aPrev[0] + ", " + aPrev[1] + ", \"" + item + "\", \"" + formato + "\")' ";
  vTxt += "onMouseOver='window.status=\"Mes anterior\"; return true;' onMouseOut='window.status=\"\"; return true;'";
  vTxt += "> < </a> &nbsp;&nbsp;";
  vTxt += meses[mes]+"&nbsp;"+ano;
  vTxt += " &nbsp;&nbsp;<a href='javascript:construirCalendario("+ aNext[0] + ", " + aNext[1] + ", \"" + item + "\", \"" + formato + "\")' ";
  vTxt += "onMouseOver='window.status=\"Siguiente mes\"; return true;' onMouseOut='window.status=\"\"; return true;'";
  vTxt += "> > </a> &nbsp;&nbsp;";
  vTxt += " &nbsp;&nbsp;<a href='javascript:construirCalendario("+ mes + ", " + (ano + 1) + ", \"" + item + "\", \"" + formato + "\")' ";
  vTxt += "onMouseOver='window.status=\"Siguiente a?o\"; return true;' onMouseOut='window.status=\"\"; return true;'";
  vTxt += "> >> </a>";
  vTxt += "</td>";
  vTxt += "</tr>";
  vTxt += "<tr class='filaDia'>";
  for ( var i = 0; i <= 6; i++)
  {
    vTxt += "<td>"+diaSemana[i]+"</td>";
  }
  vTxt += "</tr>";
  return vTxt;
}

function imprimirCalendario(mes, ano, item, formato)
{
  imprimirNuevaFila = 0;
  vPrimerDia = new Date( ano, mes, 1);
  vUltimoDia = obtenerUltimoDia(ano, mes);
  vDia = 1;
  vtxt = "";
  if ( vUltimoDia >= 30 && vPrimerDia.getDay() == 6 )
  {
    cantidad = 42 ;
  }
  else
  {
    cantidad = 35;
  }
  for ( i = 0; i < cantidad; i++)
  {
    if ( i % 7 == 0 )
    {
      imprimirNuevaFila = 0;
      vtxt += "</tr>";
    }
    if (imprimirNuevaFila == 0 )
    {
      vtxt += "<tr class='dia'>";
      imprimirNuevaFila = 1;
    }
    if ( i < vPrimerDia.getDay() || vDia  > vUltimoDia)
    {
      vtxt += "<td>&nbsp;&nbsp;</td>";
    }
    else
    {
      vtxt += "<td><a href='javascript:diaSeleccionado("+vDia+","+mes+","+ano+", \""+item+"\", \""+formato+"\");' ";
      vtxt += "onMouseOver='window.status=\"Seleccione una fecha\"; return true;' onMouseOut='window.status=\"\"; return true;'";
      vtxt += ">"+vDia+"</a></td>";
      vDia ++;
    }
  }
  return vtxt;
}

function imprimirPie(mes, ano, item, formato)
{
  var vtxt = "";
  /*
  vtxt += "<tr class='filaMes'>";
  vtxt += "<td colspan='7' class='titulo'>";
  vtxt += "<select name='irMes' class='selMes'>";
  vtxt += "<option value=0>Enero</option>";
  vtxt += "<option value=1>Febrero</option>";
  vtxt += "<option value=2>Marzo</option>";
  vtxt += "<option value=3>Abril</option>";
  vtxt += "<option value=4>Mayo</option>";
  vtxt += "<option value=5>Junio</option>";
  vtxt += "<option value=6>Julio</option>";
  vtxt += "<option value=7>Agosto</option>";
  vtxt += "<option value=8>Setiembre</option>";
  vtxt += "<option value=9>Octubre</option>";
  vtxt += "<option value=10>Noviembre</option>";
  vtxt += "<option value=10>Diciembre</option>";
  vtxt += "</select>&nbsp;";
  vtxt += "<input type='text' name='irAno' size='4' maxlength='4' value='" + ano + "'>&nbsp;" ;
  vtxt += "<input type='button' class='irbtn' value=' Ir ' onClick='javascript:construirCalendario((MM_findObj(\"irMes\").selectedIndex), MM_findObj(\"irAno\").value, \"" + item + "\", \"" + formato + "\")'";
  vtxt += "&nbsp;</td></tr>";*/
  vtxt += "  </table>";
  return vtxt;
}

function construirCalendario(mes, ano, item, formato)
{
   calTXT = "";
   calTXT += imprimirEncabezado(mes, ano, item, formato);
   calTXT += imprimirCalendario(mes, ano, item, formato);
   calTXT += imprimirPie(mes, ano, item, formato);
   mostrarCalendario(calTXT);
}

function crearCalendario(item, formato, imagen)
{
   if ( item == null )
   {
     alert ("Error al obtener par?metro requerido");
     return;
   }
   if ( !validarFormato(formato) ) { formato = "DD-MM-YYYY"; }
   // Reubicar el calendario en forma din?mica
   ubicarCalendario(imagen);
   obj = MM_findObj(item);
   if ( obj.value != "" )
   {
     var valIniciales = leerFechaInicial(item, formato);
     mes = new Number(valIniciales[0] - 1);
     ano = new Number(valIniciales[1]);
   }
   else
   {
     var hoy = new Date();
     mes = hoy.getMonth();
     ano = hoy.getYear();
   }
   
   // Solucionamos bug del mozilla? //
	if(ano < 1900){
		ano = ano + 1900;
	}

   construirCalendario(mes, ano, item, formato);
}

function ubicarCalendario ( imagen )
{
  if (imagen != "" )
  {
    var item = MM_findObj(imagen);
    var top = item.offsetTop;
    var left = item.offsetLeft;
    while (item.tagName != 'BODY') {
      if ( item.tagName == 'SPAN' || item.tagName == 'DIV' ) {
        top = top + item.offsetTop - 10;
        left = left + item.offsetLeft - 10;
      }
      if ( item.tagName == 'TABLE' || item.tagName == 'TD' || item.tagName == 'P') {
        top = top + item.offsetTop;
        left = left + item.offsetLeft;
      }
      item=item.parentElement;
    }
    if ( top > 0 && left > 0 ) {
       MM_findObj('calDiv').style.top = top;
       MM_findObj('calDiv').style.left = left + 20;
    }
  }
}

function validarFormato(formato)
{
  vret = false;
  formato = "YYYY-MM-DD";
  switch (formato)
  {
    case "DD-MM-YYYY" :
      vret = true;
      break;
    case "MM-DD-YYYY" :
      vret = true;
      break;
    case "YYYY-MM-DD" :
      vret = true;
      break;
  }
  return vret;
}

function leerFechaInicial(item, formato)
{
  var ret_arr = new Array();
  obj = MM_findObj(item);
  valor = obj.value;
  switch (formato)
  {
    case "DD-MM-YYYY" :
      ret_arr[0] = valor.substring(3,5);
      ret_arr[1] = valor.substring(6,10);
      break;
    case "MM-DD-YYYY" :
      ret_arr[0] = valor.substring(0,2);
      ret_arr[1] = valor.substring(6,10);
      break;
    case "YYYY-MM-DD" :
      ret_arr[0] = valor.substring(5,7);
      ret_arr[1] = valor.substring(0,4);
      break;
  }
   var hoy = new Date();
   if (parseInt(ret_arr[0]) < 1 || parseInt(ret_arr[0]) > 12
       || isNaN(ret_arr[0]) || ret_arr[0].length == 0)
     ret_arr[0] = (hoy.getMonth() + 1);
   if ( parseInt(ret_arr[1]) < 1950 || isNaN(ret_arr[1])
        || ret_arr[1].length == 0)
     ret_arr[1] = hoy.getYear();
   return ret_arr;
}

function construirFecha( dia, mes, ano, formato)
{
  mes += 1;
  ano = new String(ano);
  if ( dia < 10 ) { dia = "0" + dia; }
  if ( mes < 10 ) { mes = "0" + mes; }
  switch (formato)
  {
    case "DD-MM-YYYY" :
      vData = dia + "-" + mes +"-" + ano;
      break;
    case "MM-DD-YYYY" :
      vData = mes + "-" + dia + "-" + ano;
      break;
    case "YYYY-MM-DD" :
      vData = ano + "-" + mes + "-" + dia;
      break;
    default :
      vData = dia + "-" + mes +"-" + ano;
  }
  return vData;
}

function MM_findObj(n, d) { //v4.0
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && document.getElementById) x=document.getElementById(n); return x;
}

function MM_showHideLayers() { //v3.0
  var i,p,v,obj,args=MM_showHideLayers.arguments;
  for (i=0; i<(args.length-2); i+=3) if ((obj=MM_findObj(args[i]))!=null) { v=args[i+2];
    if (obj.style) { obj=obj.style; v=(v=='show')?'visible':(v='hide')?'hidden':v; }
    obj.visibility=v; }
}

function MM_dragLayer(objName,x,hL,hT,hW,hH,toFront,dropBack,cU,cD,cL,cR,targL,targT,tol,dropJS,et,dragJS) { //v3.0
  //Copyright 1998 Macromedia, Inc. All rights reserved.
  var i,j,aLayer,retVal,curDrag=null,NS=(navigator.appName=='Netscape'), curLeft, curTop;
  if (!document.all && !document.layers) return false;
  retVal = true; if(!NS && event) event.returnValue = true;
  if (MM_dragLayer.arguments.length > 1) {
    curDrag = MM_findObj(objName); if (!curDrag) return false;
    if (!document.allLayers) { document.allLayers = new Array();
      with (document) if (NS) { for (i=0; i<layers.length; i++) allLayers[i]=layers[i];
        for (i=0; i<allLayers.length; i++) if (allLayers[i].document && allLayers[i].document.layers)
          with (allLayers[i].document) for (j=0; j<layers.length; j++) allLayers[allLayers.length]=layers[j];
      } else for (i=0;i<all.length;i++) if (all[i].style&&all[i].style.position) allLayers[allLayers.length]=all[i];}
    curDrag.MM_dragOk=true; curDrag.MM_targL=targL; curDrag.MM_targT=targT;
    curDrag.MM_tol=Math.pow(tol,2); curDrag.MM_hLeft=hL; curDrag.MM_hTop=hT;
    curDrag.MM_hWidth=hW; curDrag.MM_hHeight=hH; curDrag.MM_toFront=toFront;
    curDrag.MM_dropBack=dropBack; curDrag.MM_dropJS=dropJS;
    curDrag.MM_everyTime=et; curDrag.MM_dragJS=dragJS;
    curDrag.MM_oldZ = (NS)?curDrag.zIndex:curDrag.style.zIndex;
    curLeft= (NS)?curDrag.left:curDrag.style.pixelLeft; curDrag.MM_startL = curLeft;
    curTop = (NS)?curDrag.top:curDrag.style.pixelTop; curDrag.MM_startT = curTop;
    curDrag.MM_bL=(cL<0)?null:curLeft-cL; curDrag.MM_bT=(cU<0)?null:curTop -cU;
    curDrag.MM_bR=(cR<0)?null:curLeft+cR; curDrag.MM_bB=(cD<0)?null:curTop +cD;
    curDrag.MM_LEFTRIGHT=0; curDrag.MM_UPDOWN=0; curDrag.MM_SNAPPED=false; //use in your JS!
    document.onmousedown = MM_dragLayer; document.onmouseup = MM_dragLayer;
    if (NS) document.captureEvents(Event.MOUSEDOWN|Event.MOUSEUP);
  } else {
    var theEvent = ((NS)?objName.type:event.type);
    if (theEvent == 'mousedown') {
      var mouseX = (NS)?objName.pageX : event.clientX + document.body.scrollLeft;
      var mouseY = (NS)?objName.pageY : event.clientY + document.body.scrollTop;
      var maxDragZ=null; document.MM_maxZ = 0;
      for (i=0; i<document.allLayers.length; i++) { aLayer = document.allLayers[i];
        var aLayerZ = (NS)?aLayer.zIndex:aLayer.style.zIndex;
        if (aLayerZ > document.MM_maxZ) document.MM_maxZ = aLayerZ;
        var isVisible = (((NS)?aLayer.visibility:aLayer.style.visibility).indexOf('hid') == -1);
        if (aLayer.MM_dragOk != null && isVisible) with (aLayer) {
          var parentL=0; var parentT=0;
          if (!NS) { parentLayer = aLayer.parentElement;
            while (parentLayer != null && parentLayer.style.position) {
              parentL += parentLayer.offsetLeft; parentT += parentLayer.offsetTop;
              parentLayer = parentLayer.parentElement; } }
          var tmpX=mouseX-(((NS)?pageX:style.pixelLeft+parentL)+MM_hLeft);
          var tmpY=mouseY-(((NS)?pageY:style.pixelTop +parentT)+MM_hTop);
          var tmpW = MM_hWidth;  if (tmpW <= 0) tmpW += ((NS)?clip.width :offsetWidth);
          var tmpH = MM_hHeight; if (tmpH <= 0) tmpH += ((NS)?clip.height:offsetHeight);
          if ((0 <= tmpX && tmpX < tmpW && 0 <= tmpY && tmpY < tmpH) && (maxDragZ == null
              || maxDragZ <= aLayerZ)) { curDrag = aLayer; maxDragZ = aLayerZ; } } }
      if (curDrag) {
        document.onmousemove = MM_dragLayer; if (NS) document.captureEvents(Event.MOUSEMOVE);
        curLeft = (NS)?curDrag.left:curDrag.style.pixelLeft;
        curTop = (NS)?curDrag.top:curDrag.style.pixelTop;
        MM_oldX = mouseX - curLeft; MM_oldY = mouseY - curTop;
        document.MM_curDrag = curDrag;  curDrag.MM_SNAPPED=false;
        if(curDrag.MM_toFront) {
          eval('curDrag.'+((NS)?'':'style.')+'zIndex=document.MM_maxZ+1');
          if (!curDrag.MM_dropBack) document.MM_maxZ++; }
        retVal = false; if(!NS) event.returnValue = false;
    } } else if (theEvent == 'mousemove') {
      if (document.MM_curDrag) with (document.MM_curDrag) {
        var mouseX = (NS)?objName.pageX : event.clientX + document.body.scrollLeft;
        var mouseY = (NS)?objName.pageY : event.clientY + document.body.scrollTop;
        newLeft = mouseX-MM_oldX; newTop  = mouseY-MM_oldY;
        if (MM_bL!=null) newLeft = Math.max(newLeft,MM_bL);
        if (MM_bR!=null) newLeft = Math.min(newLeft,MM_bR);
        if (MM_bT!=null) newTop  = Math.max(newTop ,MM_bT);
        if (MM_bB!=null) newTop  = Math.min(newTop ,MM_bB);
        MM_LEFTRIGHT = newLeft-MM_startL; MM_UPDOWN = newTop-MM_startT;
        if (NS) {left = newLeft; top = newTop;}
        else {style.pixelLeft = newLeft; style.pixelTop = newTop;}
        if (MM_dragJS) eval(MM_dragJS);
        retVal = false; if(!NS) event.returnValue = false;
    } } else if (theEvent == 'mouseup') {
      document.onmousemove = null;
      if (NS) document.releaseEvents(Event.MOUSEMOVE);
      if (NS) document.captureEvents(Event.MOUSEDOWN); //for mac NS
      if (document.MM_curDrag) with (document.MM_curDrag) {
        if (typeof MM_targL =='number' && typeof MM_targT == 'number' &&
            (Math.pow(MM_targL-((NS)?left:style.pixelLeft),2)+
             Math.pow(MM_targT-((NS)?top:style.pixelTop),2))<=MM_tol) {
          if (NS) {left = MM_targL; top = MM_targT;}
          else {style.pixelLeft = MM_targL; style.pixelTop = MM_targT;}
          MM_SNAPPED = true; MM_LEFTRIGHT = MM_startL-MM_targL; MM_UPDOWN = MM_startT-MM_targT; }
        if (MM_everyTime || MM_SNAPPED) eval(MM_dropJS);
        if(MM_dropBack) {if (NS) zIndex = MM_oldZ; else style.zIndex = MM_oldZ;}
        retVal = false; if(!NS) event.returnValue = false; }
      document.MM_curDrag = null;
    }
    if (NS) document.routeEvent(objName);
  } return retVal;
}