gistfile1.js

function hasClass(ele,cls) {
  return ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));
}

function addClass(ele,cls) {
  if (!this.hasClass(ele,cls))
    ele.className += " "+cls;
}

function removeClass(ele,cls) {
  if (hasClass(ele,cls)) {
    var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
    ele.className=ele.className.replace(reg,' ');
  }
}

var tabs = ['tab-block1','tab-block2','tab-block3'];
function hide() {
  for (i in tabs) {
    document.getElementById(tabs[i]).style.display='none';
	removeClass(document.getElementById('tabs-handlers').childred[i], 'active');
    removeClass(document.getElementById(tabs[i]), 'active');
  }
}

function show(id) {
  hide();
  document.getElementById(id).style.display='block';
  addClass(document.getElementById('tabs-handlers').childred[tabs.indexOf(id)], 'active');
  addClass(document.getElementById(id), 'active');
}