function getLesson(){ 
var lesson=document.getElementById("lesson_sub");
lesson.style.display="block";

} 

function hideLesson(){ 
var lesson=document.getElementById("lesson_sub") 
lesson.style.display="none";
} 

function getGirl(){ 
var lesson=document.getElementById("girl_sub");
lesson.style.display="block";

} 

function hideGirl(){ 
var lesson=document.getElementById("girl_sub") 
lesson.style.display="none";
}