function clickIE(){
if (document.all){
return false;}} 

function clickNS(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=clickNS;} 

else{
document.onmouseup=clickNS;
document.oncontextmenu=clickIE;} 

document.oncontextmenu=new Function("return false")