function Open(page,width,height) {
LeftPosition = (screen.width) ? (screen.width-width)/2 : 0;
TopPosition = (screen.height) ? (screen.height-height)/2 : 0;
OpenWin = 
this.open(page,"PopupWindow","toolbar=no,width="+width+",height="+height+",left="+LeftPosition+",top="+TopPosition+",directories=no,status=no,scrollbars=yes,resize=no,menubar=no")
}