How to disable mouse center (scroll wheel) button click using JavaScript

What is mouse center click?

Mouse wheel click

i want to disable the click event of the mouse wheel without using the alert() popup of javascript. scenario is on a webpage we press the mouse scroll wheel button and then move and down by rolling the mouse. i've done it with the alert message, which is code is  <script> onmousedonwn = stop; function stop() { if(event.button == 4 ) alert("middle mouse button"); } </script>  plz help its urgent...

I know this script. and I am searching for some sureshot method which I have not found yet i.e. without alerts.

Hence I did not post anything. thus wait. Once i find something I'll post