This article describes how to determine whether the request header contains a property to determine whether the AJAX request, such as the following
The code is as follows: <html> <head> <script language= "javascript" > function cl () {& nbsp var xmlhttp; if (window. XMLHttpRequest) { xmlhttp=new XMLHttpRequest (); } else { xmlhttp=new-ActiveXObject ("Microsoft.XMLHTTP"); } Xmlhttp.open ("POST", "ajax2.html", True); Xmlhttp.setrequestheader ("Content-type", "application/x-www-form-urlencoded"); //jquery Yui will send a containing http_x_ by default Requested_with HTTP request Header message, so it is possible to determine whether an AJAX request Xmlhttp.setrequestheader (' Http_x_requested_ With ', ' Http_x_requested_with '); xmlhttp.send (); xmlhttp.onreadystatechange=function () { if (xmlhttp.readystate==4 && xmlhttp.status==200) { alert (xmlhttp.responsetext); } } } </script> </head> <body> <input type= "button" id= BT "Name=" BT "value=" OK "onclick=" cl (); "/> </body> </html>