if (document.images) {

    var helpOn=new Image();
    helpOn.src="/images/logon/help_roll.gif";
    var helpOff=new Image();
    helpOff.src="/images/logon/help.gif";

    var termsOn=new Image();
    termsOn.src="/images/logon/terms_roll.gif";
    var termsOff=new Image();
    termsOff.src="/images/logon/terms.gif";

    var homeOn=new Image();
    homeOn.src="/images/logon/home_roll.gif";
    var homeOff=new Image();
    homeOff.src="/images/logon/home.gif";

    var logonOn=new Image();
    logonOn.src="/images/logon/logon_roll.gif";
    var logonOff=new Image();
    logonOff.src="/images/logon/logon.gif";

    var logoutTopOn=new Image();
    logoutTopOn.src="/images/buttons/logoutTop_roll.gif";
    var logoutTopOff=new Image();
    logoutTopOff.src="/images/buttons/logoutTop.gif";

  }

function highlight(imgName)
  {
  document[imgName].src = eval(imgName+'On.src');
    }

function dehighlight(imgName)
  {
    document[imgName].src = eval(imgName+'Off.src');
    }