function GetXmlHttpObject(){
	var xmlHttp;
	try
  	{
  	// Firefox, Opera 8.0+, Safari
  		xmlHttp=new XMLHttpRequest();
  	}
	catch (e)
  	{
  	// Internet Explorer
  		try
    	{
    		xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    	}
  		catch (e)
    	{
    		try
      		{
      		xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
	      	}
    		catch (e)
      		{
      		alert("Your browser does not support AJAX!");
      		return false;
      		}
    	}
  	}
	return xmlHttp;  
}


function refine(name, value, exp){
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null){
  		alert ("Your browser does not support AJAX!");
  		return;
  	}
  	xmlHttp.onreadystatechange=function(){
    	if(xmlHttp.readyState==4){
      		document.getElementById("results").innerHTML=xmlHttp.responseText;
    	}
    }
    if(name=="action"){
    	if(value=="s") value="to buy";
    	if(value=="r") value="to rent";
    }    
    url = "refine.php?ex="+exp+", "+value;
  	xmlHttp.open("GET",url,true);
  	xmlHttp.send(null);
  	
}