// ajax
var req = null;
function create_request() { 
    var request = null; 
    try { 
        request = new XMLHttpRequest(); 
    } catch (trymicrosoft) { 
        try { 
            request = new ActiveXObject("Msxml12.XMLHTTP"); 
        } catch (othermicrosoft) { 
            try { 
                request = new ActiveXObject("Microsoft.XMLHTTP"); 
            } catch (failed) { 
                request = null; 
            } 
        } 
    } 
    if (request == null) 
        alert("Error creating request object!"); 
    else 
        return request; 
} 

req = create_request(); 

function ajax_error(message) {
	if ((message == null) || (message.length <= 0)) alert("Error! Request status is " + req.status); 
	else alert(message); 
}