/*-----------------------------------------------------------
 Original
 http://archiva.jp/web/javascript/tab-menu.html

 Customized by WWW WATCH
 http://hyper-text.org/archives/2007/09/javascript_tab.shtml
------------------------------------------------------------*/
var tid;

/*--setup--*/
window.onload=function() {
tabmenu.setup = {
   tabs: document.getElementById('mainNav').getElementsByTagName('li'),
   
   pages: [
      document.getElementById('home'),
      document.getElementById('about'),
      document.getElementById('join'),
      document.getElementById('activity'),
      document.getElementById('material')
   ]
}

tabmenu.init();

}
/*--setup end--*/
var tabmenu = {
   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].onmouseover = function(){ tabmenu.showpage(this); return false; };
         tabs[i].onmouseout = function(){ clearTimeout(tid); return false; };
         tabs[i].onclick = function(){ tabmenu.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;
      }
      tid=setTimeout(function(){afterShow(pages,tabs,num)},200);
   }
}

function afterShow(pages_obj,tabs_obj,num){
	for(var i=0; i<pages_obj.length; i++) {
     if(i == num) {
        pages_obj[num].style.display = 'block';
        tabs_obj[num].className = 'selected';
     }else{
        pages_obj[i].style.display = 'none';
        tabs_obj[i].className = null;
     }
  }
}