var txtTheURL = null
var newWindow = null
var nSize     = null

function openwindow(txtTheURL, nSize ){ 
  closeNewWindow() 
  newWindow = window.open(txtTheURL,"popup","screenX=0,screenY=0,toolbar=no,location=no,directories=no,status=no,scrollbars=yes,menubar=no,resizable=yes,fullscreen=no," + nSize)
  newWindow.focus()
}

function closeNewWindow(){
  if(newWindow != null){
    newWindow.close()
  }
}