function GetXmlHttpObject()
{
    var xmlHttp=null;
    try
    {
        // Firefox, Opera 8.0+, Safari
        xmlHttp=new XMLHttpRequest();
    }
    catch (e)
    {
        //Internet Explorer
        try
        {
            xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e)
        {
            xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    
    return xmlHttp;
}

function stateChanged() 
{ 
    if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
    { 
        document.getElementById("cal").innerHTML=xmlHttp.responseText;
    } 
}

function getCal(y,m)
{
	xmlHttp=GetXmlHttpObject();
	
	if(xmlHttp==null)
	{
		alert ("Browser does not support HTTP Request");
		return;
	}

	var url = "processing/calGet.php?y="+y+"&m="+m+"";

	xmlHttp.onreadystatechange=stateChanged;
   	xmlHttp.open("GET",url,true);
    	xmlHttp.send(null);

}