function addfooterandhighlight(){
    document.getElementById("foot").innerHTML = '<p style="text-align: center; margin-top: 30px;"><a class="cssbtn" href="http://validator.w3.org/check/referer"><strong> XHTML+MathML+SVG </strong> Valid! </a></p><p style="text-align: center;"><a href="http://www.ibiblio.org/"><img src="http://www.ibiblio.org/hosted/images/sm_hosted_trans.gif" width="100" height="30" alt="hosted by ibiblio" /></a></p>';
    var num = document.URL.substr(-7, 1);
    numb=num*1
    if (typeof(numb)=="number"){
    var changed = "s" + num;
    document.getElementById(changed).style.background = "#000066";
    }
}