var xmlHttp
function rollover(minx_geo,miny_geo,maxx_geo,maxy_geo,mapW,mapH,selelem,grpstring)
{
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
{
	alert ("Browser does not support HTTP Request")
	return
} 
	var url="gethint.php"
	url=url+"?minx_geo="+minx_geo+"&miny_geo="+miny_geo+"&maxx_geo="+maxx_geo+"&maxy_geo="+maxy_geo+"&mapW="+mapW+"&mapH="+mapH+"&selelem="+selelem+"&grpstring="+grpstring
	url=url+"&sid="+Math.random()
	//alert(url);
	xmlHttp.onreadystatechange=stateChanged 
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
}


function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	{ 
		var el = document.getElementById('txtHint');
		el.innerHTML = xmlHttp.responseText; 
		//alert(el.innerHTML);
	} 
} 



function GetXmlHttpObject()
{ 
	var objXMLHttp=null
	if (window.XMLHttpRequest)
	{
		objXMLHttp=new XMLHttpRequest()
	}
	else if (window.ActiveXObject)
	{
		objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP")
	}
	return objXMLHttp
}