<SCRIPT LANGUAGE="JavaScript">
var winWidth=winHeight=250;
var top = (screen.availHeight/2)-(winHeight/2);
var left = (screen.availWidth/2)-(winWidth/2);
//X,Y坐标你自己定
window.open("","","toolbar=no,menubar=no,scrollbars=no,resizable=no,location=no, status=no,width="+winWidth+",height="+winHeight+",top="+top+",left="+left);
</SCRIPT>