clientX 属性.

Syntax:

event.clientX

The clientX event attribute returns the horizontal coordinate (according to the client area) of the mouse pointer when an event was triggered.

The client area is the current window.

e.g:

 <html>

 <head>

 <script>

 function show_coords(event)

   {

   var x=event.clientX

   var y=event.clientY

   alert("X coords: " + x + ", Y coords: " + y)

   }

 </script>

 </head>

 <body>

 <p onmousedown="show_coords(event)">Click this paragraph, and an alert box will alert the x and y coordinates of the mouse pointer.</p>

 </body>

 </html>

Note that the literal event can not be changed,or it won't work.