function clickIE4() { if (event.button == 2) { return false; } }
function clickNS4(e) { if (document.layers || document.getElementById && !document.all) { if (e.which == 2 || e.which == 3) { return false; } } }
if (document.layers) { document.captureEvents(Event.MOUSEDOWN); document.onmousedown = clickNS4; }
else if (document.all && !document.getElementById) { document.onmousedown = clickIE4; }
document.oncontextmenu = new Function("return false");