function openpreview( startpage, windowName, windowOption ) {
  p_win=window.open(startpage, windowName, windowOption )
  p_win.focus()
  setTimeout('p_win.focus()',200)
}

function openorfocus( startpage, windowName, windowOption ) {
  if ( typeof( p_win ) != 'undefined' ) {
    if (!p_win.closed) {
      p_win.focus()
      p_win.location.href=startpage
    }
    else
      openpreview(startpage, windowName, windowOption);
  }
  else
    openpreview(startpage, windowName, windowOption);
}