function update_calendar(month,year){

  if(document.getElementById("div_calendar").style.display == ""){
      document.getElementById("div_calendar").style.display = "block";
  }

document.getElementById("div_calendar").innerHTML  = '<img src="layout/images/ajax-loader.gif" /> loading calendar...';


var url = 'calendar.php';

if(month)
	{
		url += '?month=' + month  +  '&year=' + year;
	}


new Ajax.Updater('div_calendar',url,
  {
    method:'get',
    onSuccess: function(){
	      var response = transport.responseText || "no response text";
				document.getElementById("div_calendar").innerHTML  = '';
        document.getElementById("div_calendar").innerHTML = response;
    },
    onFailure: function(){ alert('Something went wrong...') }
  });

}