jQuery Ajax返回整个页面

Question

I have a jquery-ajax function that sends data to a php script and the problem is with the return value, it returns the whole page instead of single value.

Thank you for your time and help.

$("#ajaxBtn").click(function(){
  var inputText = $("#testText").val();

  $.ajax({ type: "POST",
    url: "index.php",
    data: "testAjax="+inputText,
    dataType: "html",
    success: function(html){
      alert(html);
    }
  });
});