if (document.images)
{
  img1= new Image(110,25); 
  img1.src="/images/bkgd-log-in-on.gif"; 

  img2= new Image(240,55); 
  img2.src="/images/bkgd-navbutton-hover.jpg";
}

function showBox(elementID) {
    var c = document.getElementById(elementID).className;
    if (c == "show") {
        document.getElementById(elementID).className = "hidden";
    } else {
        document.getElementById(elementID).className = "show";
    }
}