var WindowObjectReferenceOfRequestedPopup;
function openPopup(strUrl, strTarget)
{
windowWidth = 700;
windowHeight = 650;
windowLeft = 60;
windowTop = 40;
if (WindowObjectReferenceOfRequestedPopup == null || WindowObjectReferenceOfRequestedPopup.closed)
  {
  WindowObjectReferenceOfRequestedPopup = window.open(strUrl, strTarget, "top=" + windowTop + ",left=" + windowLeft + ",width=" + windowWidth + ",height=" + windowHeight + ",resizable,statusbar");
  }
  else
  {
  WindowObjectReferenceOfRequestedPopup.focus();
  }
}