I have a peace of jquery code:

var new = checkCP(somedata);
 if(new=="hi"){
   alert("Welcom");
 }

 function checkCP(jsData){

            $.ajax({
                type: "POST",
                url: "Process.php",
                data: jsData,
                dataType: "json",
                success: function(data){
                    if(data.match==1)
                  return "hi";  
                else
                  return "bye";
                }
          });

        }

I don't know why the welcome alert never show up . I checked everything , even on PHP file the result is 1 but apparently before It wait for ajax respond it passes the

  if(new=="hi"){
   alert("Welcom");
 }

So is there anyway to wait for ajax respond then read the rest of codes in jQuery ? Thanks.