function click(e) { 
if (document.all) { 
if (event.button==2||event.button==3) { 
oncontextmenu='return false'; 
} 
} 
if (document.layers) { 
if (e.which == 3) { 
oncontextmenu='return false'; 
} 
} 
} 
if (document.layers) { 
document.captureEvents(Event.MOUSEDOWN); 
} 
document.onmousedown=click;