function gup( name ){  name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");  var regexS = "[\\?&]"+name+"=([^&#]*)";  var regex = new RegExp( regexS );  var results = regex.exec( window.location.href );  if( results == null )    return "";  else    return results[1];}
function setStyle(objId, style, value){
   document.getElementById(objId).style[style]= value;
}
function setVisibility(objId, sVisibility) {

        var obj = document.getElementById(objId);

         obj.style.visibility = sVisibility;
      }

var par_param = gup( 'par' );
function changeClass(){
document.getElementById("idElement").setAttribute("class", "myClass");
}