function pintaCalendar(field, ObjetoImagen){
//Si existen calendarios los eliminamos;
destroyCalendar();
obj = document.getElementById(field);
dateField = field;
myDate = new Date();
if(obj.value!="")
{
myDateArray = obj.value.split("/");
myDate.setFullYear(myDateArray[2], myDateArray[1]-1, myDateArray[0]);
if(myDate == "NaN")
	myDate = new Date();
}
/* thisMonth = new calendar('thisMonth',new Date());*/
thisMonth = new calendar('thisMonth',myDate);
container = document.createElement("div");
container.id = 'calContainer';
container.className = 'divContainer';
containerIE = document.createElement("div");
containerIE.id = 'calContainerIE';
containerIE.className = 'divContainerIE';
ieworkaround = document.createElement("iframe");
//ieworkaround.className= 'divContainerIE';
ieworkaround.src='blanca?OpenPage';
container.innerHTML=thisMonth.write();
containerIE.appendChild(ieworkaround);
//DJC 23/12/08  Calcular posición del calendario a partir de la imagen del botón
  var x = ObjetoImagen.offsetLeft -100;
  var y = ObjetoImagen.offsetTop + ObjetoImagen.offsetHeight;
  
  var parent = ObjetoImagen;
  while (parent.offsetParent) {
    parent = parent.offsetParent;
    x += parent.offsetLeft;
    y += parent.offsetTop;
  }
  // 200 es la anchura del calendario
if((x+200)>document.body.clientWidth){
   x = (x-200) + ObjetoImagen.offsetWidth
  }
if(document.getElementById('MainMenu'))
{
container.style.top= y+'px';
container.style.left= x+'px';
containerIE.style.top= y+'px';
containerIE.style.left= x+'px';
//container.style.top='160';
//container.style.left='500';
//containerIE.style.top='160';
//containerIE.style.left='500';
} else {
container.style.top= y+'px';
container.style.left= x+'px';
containerIE.style.top= y+'px';
containerIE.style.left= x+'px';
//container.style.top='160';
//container.style.left='550';
//containerIE.style.top='160';
//containerIE.style.left='550';
};
document.getElementsByTagName('body')[0].appendChild(container);
document.getElementsByTagName('body')[0].appendChild(containerIE);
}
function destroyCalendar()
{
cal = document.getElementById('calContainer');
calIE = document.getElementById('calContainerIE');
if(cal!=null)
	cal.parentNode.removeChild(cal);
if(calIE!=null)
	calIE.parentNode.removeChild(calIE);
}
   var days = new Array('Lu','Ma','Mi',
      'Ju','Vi','Sa','Do');
   var months = new Array('Enero','Febrero','Marzo','Abril','Mayo','Junio','Julio','Agosto','Septiembre','Octubre','Noviembre','Diciembre');
   // Constructor
   function calendar(id, d){
      this.id = id;
      this.dateObject = d;
      this.write = writeCalendar;
      this.length = getLength(d.getMonth(),d.getFullYear());
      this.month = d.getMonth();
      this.date = d.getDate();
      this.day = d.getDay();
      this.year = d.getFullYear();
      this.getFormattedDate = getFormattedDate;
      this.dateToPrint = dateToPrint;
      // get the first day of the month's day
      d.setDate(1);
      this.firstDay = d.getDay()-1; // corrección para que la semana empiece el lunes
      if (this.firstDay < 0) {                   // corrección para que la semana empiece el lunes
	this.firstDay = 6;
      }
      // then reset the date object to the correct date
      d.setDate(this.date);
   }
   function changeDate(td,cal){
      // Some JavaScript trickery
      // Change the cal argument to the existing 
      // calendar object
      // This is why the first argument in the 
      // constructor must match the variable name
      // The cal reference also allows for 
      // multiple calendars on a page
      cal = eval(cal);
      document.getElementById(cal.id + 
         "selected").className = "days";
      document.getElementById(cal.id + 
         "selected").id = "";
      td.className = "date";
      td.id = cal.id + "selected";
      // set the calendar object to the new date
      cal.dateObject.setDate(td.firstChild.nodeValue);
      cal = new calendar(cal.id,cal.dateObject);
      // here is where you could react to a date change&#151;
      // I'll just display the formatted date
	td.onMouseOut="td.className=\'date\'";
	document.getElementById(dateField).value=cal.dateToPrint();
	destroyCalendar();
   }
   function changeMonth(mo,cal){
// more trickery!
      cal = eval(cal);
      // The Date object is smart enough to 
      // know that it should roll over in December
      // when going forward and in January 
      // when going back
      cal.dateObject.setMonth(cal.dateObject.getMonth() + mo);
      cal = new calendar(cal.id,cal.dateObject,cal.pix);
      cal.formattedDate = cal.getFormattedDate();
      document.getElementById('calContainer').innerHTML = cal.write();     
   }
   
   function getFormattedDate(){
       return this.date + '/' + (this.month+1) + '/' + 
         this.year;
   }
  function dateToPrint()
{
if(this.date<10)
	this.date = '0'+this.date;
if(this.month<9){
	this.month = '0'+(this.month+1);
} else {
	this.month = this.month+1;
}
       return this.date + '/' + this.month + '/' + 
         this.year;
}
  function getLength(mes,anyo){
      // thirty days has September...
      switch(mes){
         case 1:
            if ((anyo%4==0 && 
              anyo%100!=0) || 
              anyo%400==0)
               return 29; // leap year
            else
               return 28;
         case 3:
            return 30;
         case 5:
            return 30;
         case 8:
            return 30;
         case 10:
            return 30
         default:
            return 31;
      }
   }
  function writeCalendar(){
      var calString = '<div id="calContainer">';
      // write month and year at top of table
      calString += '<table id="cal' + this.id + 
         '" cellspacing="0" width="200"' + 
         ' style="border:1px #777777 solid;">';
      // write the month
// mod to draw navigation on top
      calString += '<tr><th class="month" onClick="changeMonth(-12,\'' + 
         this.id + '\')" style="cursor:pointer;"><<</th><th class="month" onClick="changeMonth(-1,\'' + 
         this.id + '\')" style="cursor:pointer;"><</th><th colspan=3 class="month" nowrap>' + 
         months[this.month] + ', ' + this.year + 
         '</th><th class="month" onClick="changeMonth(1,\'' + 
         this.id + '\')" style="cursor:pointer;">></th><th class="month" onClick="changeMonth(12,\'' + 
         this.id + '\')" style="cursor:pointer;">>></th></tr>';
//      calString += '<tr><th colspan="7" class="month">' + 
 //        months[this.month] + ', ' + this.year + 
 //        '</th></tr>';
      // write a row containing days of the week
      calString += '<tr>';
      
      for(i=0;i<days.length;i++){
         calString += '<th class="dayHeader">' + 
            days[i].substring(0,3) + '</th>';
      }
      // write the body of the calendar
      calString += '<tr>';
      // create 6 rows so the calendar doesn't resize
      for(j=0;j<42;j++){
         var displayNum = (j-this.firstDay+1);
         if(j<this.firstDay){
            // write the leading empty cells
            calString += '<td class="empty">&nbsp;</td>';
         }else if(displayNum==this.date){
            calString += '<td id="' + this.id + 
              'selected" class="date" onMouseOut="if(this.id==\'\')this.className=\'days\'" onMouseOver=""' + 
              'onClick="javascript:changeDate(this,\'' + 
              this.id + '\')">' + displayNum + '</td>';
         }else if(displayNum > this.length){
            // Empty cells at bottom of calendar
            calString += '<td class="empty">&nbsp;</td>';
         }else{
            // the rest of the numbered cells
            calString += '<td id="" class="days" onMouseOut="if(this.id==\'\')this.className=\'days\'" onMouseOver="this.className=\'dateOver\'"' + 
              'onClick="javascript:changeDate(this,\'' + 
              this.id + '\')">' + displayNum + '</td>';
         }
         if(j%7==6){
            calString += '</tr><tr>';
         }
      }
      // close the last number row
      calString += '</tr>';
      calString += '</table>';
	calString += '<div style="position:relative; text-align:center; top: -13px; width:34px; left: 165px; z-index: 10; display: block; cursor:pointer" onclick="destroyCalendar()" class="month">cerrar</div>';
      calString += '</div>';
      return calString;
   }