var myWin=null;

function openWin(winName,htmlFile,mywidth,myheight,myscr) {
  if (myWin == null || myWin.closed) {
    myWin=window.open(htmlFile,winName,
      "width="+mywidth+",height="+myheight+",status="+myscr);
  }
  else {
    myWin.location.href = htmlFile;
  }
}