function changeContentA(){
	document.getElementById('main').innerHTML = '<div id="main_scroll"><img src="images/lizzy-learn.jpg"></div>';}
	
function changeContent0(){
	document.getElementById('main').innerHTML = '<div id="main_scroll"><img src="images/lizzy-prereading-contents.jpg"></div>';}

function changeContent1(){
	document.getElementById('main').innerHTML = '<div id="main_scroll"><img src="images/lizzy-level1-contents.jpg"></div>';}

function changeContent2(){
	document.getElementById('main').innerHTML = '<div id="main_scroll"><img src="images/lizzy-level2-contents.jpg"></div>';}
	
function changeContent3(){
	document.getElementById('main').innerHTML = '<div id="main_scroll"><img src="images/lizzy-level3-contents.jpg"></div>';}
	
function changeContent4(){
	document.getElementById('main').innerHTML = '<div id="main_scroll"><img src="images/lizzy-level4-contents.jpg"></div>';}
	
function changeContent9(){
	document.getElementById('main').innerHTML = '<div id="main_scroll"><img src="images/lizzy-assessment.jpg"></div>';}