How to Prevent Users to Press F5 key (Refresh button)

Some times we want to prevent user to Press F5 key to prevent Page Refresh.
This Script works fine.(As i tested in IE.)
Paste this code in the Head Section of your Page

document.onkeydown =
function(){
if(window.event && window.event .keyCode == 116)
{
// Capture and remap F5
window.
event.keyCode = 505;
}
if(window.event && window.event .keyCode == 505)
{
// New action for F5
return false;
// Must return false or the browser will refresh anyway
} }