var showFunction1 = function() {
    $$('.tabHidden').setStyle('display', 'none');
    $$('.active-tab1').removeClass('active-tab1');
    this.setStyle('display', 'block');
    $('tabP1').addClass('active-tab1');
}
var showFunction2 = function() {
$$('.tabHidden').setStyle('display', 'none');
$$('.active-tab1').removeClass('active-tab1');
    this.setStyle('display', 'block');
    $('tabP2').addClass('active-tab1');
}
var showFunction3 = function() {
    $$('.tabHidden').setStyle('display', 'none');
    $$('.active-tab1').removeClass('active-tab1');
    this.setStyle('display', 'block');
    $('tabP3').addClass('active-tab1');
}
var showFunction4 = function() {
    $$('.tabHidden').setStyle('display', 'none');
    $$('.active-tab1').removeClass('active-tab1');
    this.setStyle('display', 'block');
    $('tabP4').addClass('active-tab1');
}
window.addEvent('domready', function() {
    var elOneB = $('tab1');
    var elTwoB = $('tab2');
    var elThreeB = $('tab3');
    var elFourB = $('tab4');
    addEvent('load', showFunction1.bind(elOneB));
    elOneB.addClass('tabHidden');
 
    $('tabP1').addEvent('click', showFunction1.bind(elOneB));
    $('tabP2').addEvent('click', showFunction2.bind(elTwoB));
    $('tabP3').addEvent('click', showFunction3.bind(elThreeB));
    $('tabP4').addEvent('click', showFunction4.bind(elFourB));
});