// for Netscape 4+ and IE 4+

var popWin = null    // use this when referring to pop-up window

var winCount = 0

var winName = "popWin"

function openPopWin(winURL, winWidth, winHeight, winFeatures, winLeft, winTop){

  var d_winLeft = 20  // default, pixels from screen left to window left

  var d_winTop = 20   // default, pixels from screen top to window top

  winName = "popWin" + winCount++ //unique name for each pop-up window

  closePopWin()           // close any previously opened pop-up window

  if (openPopWin.arguments.length >= 4)  // any additional features? 

    winFeatures = "," + winFeatures

  else 

    winFeatures = "" 

  if (openPopWin.arguments.length == 6)  // location specified

    winFeatures += getLocation(winWidth, winHeight, winLeft, winTop)

  else

    winFeatures += getLocation(winWidth, winHeight, d_winLeft, d_winTop)

  popWin = window.open(winURL, winName, "width=" + winWidth 

           + ",height=" + winHeight + winFeatures)

  }

function closePopWin(){    // close pop-up window if it is open 

  if (navigator.appName != "Microsoft Internet Explorer" 

      || parseInt(navigator.appVersion) >=4) //do not close if early IE

    if(popWin != null) if(!popWin.closed) popWin.close() 

  }

function getLocation(winWidth, winHeight, winLeft, winTop){

  return ""

  }


function getLocation(winWidth, winHeight, winLeft, winTop){

  var winLocation = ""

  if (winLeft < 0)

    winLeft = screen.width - winWidth + winLeft

  if (winTop < 0)

    winTop = screen.height - winHeight + winTop

  if (winTop == "cen")

    winTop = (screen.height - winHeight)/2 - 20

  if (winLeft == "cen")

    winLeft = (screen.width - winWidth)/2

  if (winLeft>0 & winTop>0)

    winLocation =  ",screenX=" + winLeft + ",left=" + winLeft	

                + ",screenY=" + winTop + ",top=" + winTop

  else

    winLocation = ""

  return winLocation

  }