// Use this function to control placement of pop-up window
// in Netscape 4+ and Internet Explorer 4+
function openPopImgWin(imgWinName, windowWidth, windowHeight){
  var leftX = 20  // distance of window's left side from left of screen
  var topY = 20   // distance of window's top side from top of screen
  var winFeatures = "toolbar=no,scrollbars=no,resizable=no,width=" 
    + windowWidth + ",height=" + windowHeight
  if (leftX>0){
    winFeatures += ",screenX=" + leftX + ",left=" + leftX	
                + ",screenY=" + topY + ",top=" + topY
    }
  return window.open("pimg.htm", imgWinName, winFeatures)
  }