var popWin = ""; function openwin(url, strWidth, strHeight) { if (popWin != "") {popWin.close()} leftStr = (screen.width-strWidth)/2; topStr = (screen.height-strHeight)/2-50; windowProperties = "toolbar=no,menubar=no,scrollbars=yes,statusbar=no,height="+strHeight+",width="+strWidth+",left="+leftStr+",top="+topStr+""; popWin = window.open(url,'newWin',windowProperties); }