var winNewWindow = null;
function PopWin(strURL,numWidth,numHeight) {
  numXPos = (window.screen.width/2) - (numWidth/2);
  numYPos = (window.screen.height/2) - (numHeight/2);
  if (winNewWindow != null) {
	  if (winNewWindow.closed == false) {
		  winNewWindow.close();
	  }
  }
  winNewWindow = window.open(strURL, 'winNewWindow','toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=1,resizable=1,left=' + numXPos + ',top=' + numYPos + ',screenX=' + numXPos + ',screenY=' + numYPos + ',width=' + numWidth + ',height=' + numHeight);
		winNewWindow.focus();
}