Restrict the Right Click on Mouse Using Java Script

Some Browsers event.button=2 is the Right Click (Ex : IE) and Some Browsers event.button=3 is the Right Click

<script language="JavaScript" type="text/javascript">
    document.onmousedown=click
    function click() 
    {
        if ((event.button==2) || (event.button==3)) 
        {
            alert("I said NO right clicking! click ok to exit LMAO!");
        } 
    }
</script>