var xmlHttp;
var xmlFile;
var queryString;

function createxmlHttpRequest() {
    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;        
            }      
        }    
    }
//	if (window.ActiveXObject) {
//		xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
//	}
//	else if (window.xmlHttpRequest) {
//		xmlHttp = new xmlHttpRequest();
//	}
}

function handleStateChange() {
    if (xmlHttp.readyState == 4) {
	    if (xmlHttp.status == 200) {
		    //clearPreviousResults();
		    parseResults();
	    }
	    else if (xmlHttp.status == 500) {

	    }
    }
}    

function doRequestUsingGET(url, xmlTopic) {
    xmlFile = xmlTopic;
	createxmlHttpRequest();
	
	if (queryString != "") {
	    url = url + "?" + queryString;
	}
	xmlHttp.onreadystatechange = handleStateChange;
	xmlHttp.open("get", url , true);
	xmlHttp.send(null);
	ShowStatus("load");
}

function doRequestUsingPOST(url, postString, xmlTopic) {
//    try {
        xmlFile = xmlTopic;
	    createxmlHttpRequest();	    
	    xmlHttp.open("post", url, true);	    
	    xmlHttp.onreadystatechange = handleStateChange;	    	    
	    xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;");		    
        /*xmlHttp.setRequestHeader("Content-Type","text/xml");
        xmlHttp.setRequestHeader("Cache-Control","no-cache");
        xmlHttp.setRequestHeader("Pragma","no-cache");
        xmlHttp.SetRequestHeader("Content-Type","application/xml");
        xmlHttp.SetRequestHeader("Accept","application/xml");
        xmlHttp.setRequestHeader("Connection", "Keep-Alive");*/
	    xmlHttp.send(postString);
	    ShowStatus("load");
//    }
//    catch (e) {
//        alert("Error");
//    }
}
/*
function clearPreviousResults() {
	var header = document.getElementById("header");
	if (header.hasChildNodes()) {
		header.removeChild(header.childNodes[0]);
	}
	
	var tableBody = document.getElementById("resultsBody");
	while (tableBody.childNodes.length > 0) {
		tableBody.removeChild(tableBody.childNodes[0]);
	}
}
*/