Ajax jquery .load（）错误404

 $("#options li").click(function(){
  $("#mcont").load("ah.html",function(responseTxt,statusTxt,xhr){
    if(statusTxt=="success")
      alert("External content loaded successfully!");
    if(statusTxt=="error")
      alert("Error: "+xhr.status+": "+xhr.statusText);
    });
 });

I'm new to ajax and I tried this jquery call but it gives me error 404. ah.html is in the same directory with my page.