var http_request = false;   
function createXMLHttp()
{        
	http_request = false;
	if (window.XMLHttpRequest)
	{ 
		http_request = new XMLHttpRequest();
		if (http_request.overrideMimeType) 
		{
			http_request.overrideMimeType('text/xml');
		}
	} 
	else if (window.ActiveXObject)
	{ 
		try 
		{
			http_request = new ActiveXObject("Msxml2.XMLHTTP");
		} 
		catch (e) 
		{
			try 
			{
				http_request = new ActiveXObject("Microsoft.XMLHTTP");
			} 
			catch (e) {}
		}
	}
	if (!http_request) {
		alert('Giving up :( Cannot create an XMLHTTP instance');
		return false;
	} 
}   
    
function Request(page, para, work, pst)
{   
    createXMLHttp(); 
    var url=page+"?"+para;
    http_request.onreadystatechange = Response;   
    http_request.open(pst,url,work);   
    http_request.send(null);   
}   
       
function Response()
{   
    if(http_request.readyState == 4)
    {   
        if(http_request.status == 200)
        {   
        	var strString = http_request.responseText;
        	return strString;
        } 
        else
        {
            return(http_request.status);
        	//alert('There was a problem with the request.');
        }   
    }   
}

/*
page:ajax̨ҳ
para:̨ҳ
work:ͬ첽ʽ
    true:첽ʽ
    false:ͬʽ
pst:ύʽ
    post:
    get:
*/
function ajax(page, para, work, pst)
{
    var str,aaa;
    createXMLHttp();
    Request(page, para, work, pst);
    str = Response();
    return str;
}