HOW to close with oncontextmenu();

[admin]

hi friends,
do u know how to close window using ..oncontextmenu();

<SCRIPT LANGUAGE=javascript FOR=document EVENT=oncontextmenu>
<!--
document_oncontextmenu();
//-->
</SCRIPT>
function document_oncontextmenu()
{
window.close()
}

IT DOSENT WORK