var tab = {
    init: function(){
    var tabs = this.setup.tabs;
    var pages = this.setup.pages;
     
    for(i=0; i<pages.length; i++) {
    if(i !== 0) pages[i].style.display = 'none';
    tabs[i].onclick = function(){ tab.showpage(this); return false; };
    }
    },
     
    showpage: function(obj){
    var tabs = this.setup.tabs;
    var pages = this.setup.pages;
    var num;
     
    for(num=0; num<tabs.length; num++) {
    if(tabs[num] === obj) break;
    }
     
    for(var i=0; i<pages.length; i++) {
    if(i == num) {
    pages[num].style.display = 'block';
    tabs[num].className = 'present';
    }
    else{
    pages[i].style.display = 'none';
    tabs[i].className = null;
    }
    }
    }
    }