$(document).ready(function(){
function changeSource1()
  {
  document.getElementById("content").src="1.html"
  document.getElementById("content").height="324"
  document.getElementById("Advanced Test").innerHTML="<b>Advanced Test</b>";
  document.getElementById("Novice Test").innerHTML="Novice Test";
  document.getElementById("Questions: Tier I").innerHTML="Questions: Tier I";
  document.getElementById("Questions: Tier II").innerHTML="Questions: Tier II";
  document.getElementById("Questions: Tier III").innerHTML="Questions: Tier III";
  }
 function changeSource2()
  {
  document.getElementById("content").src="23.html"
  document.getElementById("content").height="324"
    document.getElementById("Advanced Test").innerHTML="Advanced Test";
  document.getElementById("Novice Test").innerHTML="<b>Novice Test</b>";
  document.getElementById("Questions: Tier I").innerHTML="Questions: Tier I";
  document.getElementById("Questions: Tier II").innerHTML="Questions: Tier II";
  document.getElementById("Questions: Tier III").innerHTML="Questions: Tier III";
  } 
  function changeSource3()
  {
  document.getElementById("content").src="contier1.htm"
  document.getElementById("content").height="880"
    document.getElementById("Advanced Test").innerHTML="Advanced Test";
  document.getElementById("Novice Test").innerHTML="Novice Test";
  document.getElementById("Questions: Tier I").innerHTML="<b>Questions: Tier I</b>";
  document.getElementById("Questions: Tier II").innerHTML="Questions: Tier II";
  document.getElementById("Questions: Tier III").innerHTML="Questions: Tier III";
  }
    function changeSource4()
  {
  document.getElementById("content").src="contier2.htm"
  document.getElementById("content").height="1450"
    document.getElementById("Advanced Test").innerHTML="Advanced Test";
  document.getElementById("Novice Test").innerHTML="Novice Test";
  document.getElementById("Questions: Tier I").innerHTML="Questions: Tier I";
  document.getElementById("Questions: Tier II").innerHTML="<b>Questions: Tier II</b>";
  document.getElementById("Questions: Tier III").innerHTML="Questions: Tier III";
  }
      function changeSource5()
  {
  document.getElementById("content").src="contier3.htm"
  document.getElementById("content").height="590"
    document.getElementById("Advanced Test").innerHTML="Advanced Test";
  document.getElementById("Novice Test").innerHTML="Novice Test";
  document.getElementById("Questions: Tier I").innerHTML="Questions: Tier I";
  document.getElementById("Questions: Tier II").innerHTML="Questions: Tier II";
  document.getElementById("Questions: Tier III").innerHTML="<b>Questions: Tier III</b>";
  }

	var sections = $("#menu li");
	var loading = $("#loading");
	var content = $("#content");
	
	sections.click(function(){

		switch(this.id){
			case "Advanced Test":
				content.slideUp();
				onclick=changeSource1();
				content.slideDown();
				break;
			case "Novice Test":
				content.slideUp();
				onclick=changeSource2();
				content.slideDown();
				break;
			case "Questions: Tier I":
				content.slideUp();
				onclick=changeSource3();
				content.slideDown();
				break;
			case "Questions: Tier II":
				content.slideUp();
				onclick=changeSource4();
				content.slideDown();
				break;
							case "Questions: Tier III":
				content.slideUp();
				onclick=changeSource5();
				content.slideDown();
				break;
			default:
				break;
		}
	});

	
});