var request;
var cn; 
function getCat(catnum,srt,affid){
    cn=catnum;
	if(catnum)  {
		var url="index.cgi?cat="+catnum+"&s="+srt+"&a="+affid;
		httpRequest("GET",url,true);   
	}
}
function handleResponse(){
    if(request.readyState == 4){
        if(request.status == 200){
            var info = request.responseText;
            document.getElementById("menu"+cn).innerHTML = info ;
        } else {
            alert("A problem occurred with communication between the XMLHttpRequest object and the server.");
	        window.open("search.cgi?cat="+cn);
        }
    }
}
function initReq(reqType,url,bool){
    request.onreadystatechange=handleResponse;
    request.open(reqType,url,bool);
    request.send(null);
}
function httpRequest(reqType,url,asynch){
    if(window.XMLHttpRequest){
        request = new XMLHttpRequest();
    } else if (window.ActiveXObject){
        request=new ActiveXObject("Msxml2.XMLHTTP");
        if (! request){
            request=new ActiveXObject("Microsoft.XMLHTTP");
        }
     }
    if(request){
       initReq(reqType,url,asynch);
    }  else {
       alert("Your browser is not compatible with this function.");
       window.open("search.cgi?cat="+cn);
    }
}