js 强制弹出窗口代码研究－又一款代码

<script language="JavaScript">
var paypopupURL = "https://www.jb51.net";
var randkey = '13'; //bypass IE functions
function setupActiveX(){
document.write(' <INPUT ID="autoHit" TYPE="TEXT" ONKEYPRESS="showActiveX()">');
}
function openActiveX(){
document.getElementById('autoHit').fireEvent("onkeypress",(document.createEventObject().keyCode=escape(randkey).substring(1)));
}
function showActiveX(){
var newWindow=window.open(paypopupURL,'abcdefg','width=200,height=200,top=50,left='+(screen.width-250));
}
setupActiveX();
openActiveX();
self.focus();
</script>