<!--
NS4 = (document.layers) ? 1 : 0;
IE4 = (document.all) ? 1 : 0;
DOM = (document.getElementById) ? 1 : 0;

function showlayer(layername) {
 if (NS4) {
  document.layers[layername].visibility = "show";
 }else if (DOM){
  document.getElementById(layername).style.visibility="visible";
 }else if (IE4){
  document.all[layername].style.visibility="visible";
 }
}

function hidelayer(){
 for (i=1;i<3;i++) {
 layername='solution'+i
 if (NS4) {
  document.layers[layername].visibility = "hide";
 }else if (DOM){
  document.getElementById(layername).style.visibility="hidden";
 }else if (IE4){
  document.all[layername].style.visibility="hidden";
 }
 }
}

//-->