var version4 = (navigator.appVersion.charAt(0) == "4"); 
var popupHandle;
function closePopup() {
  if(popupHandle != null && !popupHandle.closed) popupHandle.close();
}
function displayPopup(position,url,name,height,width,evnt) {
  // position=1 POPUP: makes screen display up and/or left, down and/or right 
  // depending on where cursor falls and size of window to open
  // position=2 CENTER: makes screen fall in center

  if (height>768) {
    height='768';
    var properties = "toolbar=0, location=0, height = " + height;
      properties = properties + ", scrollbars=1, width=" + width;
  } else {
    var properties = "toolbar=0, location=0, height = " + height;
     properties = properties + ", width=" + width;
  }

  var leftprop, topprop, screenX, screenY, cursorX, cursorY, padAmt;
  if (navigator.appName == "Microsoft Internet Explorer") {
    screenY = document.body.offsetHeight;
    screenX = window.screen.availWidth;
  }
  else {
    screenY = window.outerHeight
    screenX = window.outerWidth
  }
  if (position == 1) { 
    // if POPUP not CENTER
    cursorX = evnt.screenX;
    cursorY = evnt.screenY;
    padAmtX = 10;
    padAmtY = 10;
    if ((cursorY + height + padAmtY) > screenY) {
      // make sizes a negative number to move left/up
      padAmtY = (-30) + (height * -1);
      // if up or to left, make 30 as padding amount
    }
    if ((cursorX + width + padAmtX) > screenX) {
      padAmtX = (-30) + (width * -1);	
      // if up or to left, make 30 as padding amount
    }
    if (navigator.appName == "Microsoft Internet Explorer") {
      leftprop = cursorX + padAmtX;
      topprop = cursorY + padAmtY;
    } else {
      leftprop = (cursorX - pageXOffset + padAmtX);
      topprop = (cursorY - pageYOffset + padAmtY);
    }
  } else {
  leftvar = (screenX - width) / 2;
  rightvar = ((screenY - height) / 2)-200;
    if (navigator.appName == "Microsoft Internet Explorer") {
      leftprop = leftvar;
      topprop = (rightvar);
    } else {
      leftprop = (leftvar - pageXOffset);
      topprop = (rightvar - pageYOffset);
    }
  }
  if(evnt != null) {
    properties = properties + ", left = " + leftprop;
    properties = properties + ", top = " + topprop;
  }
  closePopup();

     popupHandle = open(url,name,properties);
}