function getElementsByClassName(node,classname) {
	if (node.getElementsByClassName)
		return node.getElementsByClassName(classname);
	else {
    var retnode = [];
    var myclass = new RegExp('\\b'+classname+'\\b');
    var elem = node.getElementsByTagName('*');
    for (var i = 0; i < elem.length; i++) {
    var classes = elem[i].className;
    if (myclass.test(classes)) retnode.push(elem[i]);
    }
    return retnode;
	}
}
function switchRoom(room){
  var p=getElementsByClassName(document,'tPage');
  for (var i=0; i<p.length; i++){
    idP=p[i].id;
    document.getElementById(idP).style.display="none";
  }
  document.getElementById(room).style.display="block";
}