function setupTabs() {
	attachEventListener(document.getElementById('nav_bio'),'click',showBio,false);
	if(document.getElementById('nav_cou')) attachEventListener(document.getElementById('nav_cou'),'click',showCou,false);
	if(document.getElementById('nav_sch')) attachEventListener(document.getElementById('nav_sch'),'click',showSch,false);

	checkLength();
}

function checkLength() {
  if(document.getElementById('scholarship').innerHTML.length == 0) {
    document.getElementById('nav_sch').style.display = 'none';
    document.getElementById('nav_cou_link').className = 'omega';
  } else {
    document.getElementById('nav_sch').style.display = 'block';
  }

  if(document.getElementById('courses').innerHTML.length == 0) {
    document.getElementById('nav_cou').style.display = 'none';
    if(document.getElementById('scholarship').innerHTML.length == 0) {
      document.getElementById('nav_bio_link').className = 'omega';
    }
  } else {
    document.getElementById('nav_cou').style.display = 'block';
  }

}

function showBio() {
	clearTabs();
	document.getElementById('nav_bio').className = 'active';
	document.getElementById('nav_bio').style.zIndex = 5;
	document.getElementById('biography').style.display = 'block';
}

function showCou() {
	clearTabs();
	document.getElementById('nav_cou').className = 'active';
	document.getElementById('nav_cou').style.zIndex = 5;
	document.getElementById('courses').style.display = 'block';
}

function showSch() {
	clearTabs();
	document.getElementById('nav_sch').className = 'active';
	document.getElementById('nav_sch').style.zIndex = 5;
	document.getElementById('scholarship').style.display = 'block';
}

function clearTabs() {
	document.getElementById('nav_bio').className = '';
	document.getElementById('nav_cou').className = '';
	document.getElementById('nav_sch').className = '';

	document.getElementById('nav_bio').style.zIndex = 2;
	document.getElementById('nav_cou').style.zIndex = 1;
	document.getElementById('nav_sch').style.zIndex = 0;
	
	document.getElementById('biography').style.display = 'none';
	document.getElementById('courses').style.display = 'none';
	document.getElementById('scholarship').style.display = 'none';
}

addLoadEvent(setupTabs);