// JavaScript Document
function rollover(id){
document.getElementById(id).style.background="url('image/nav_over.jpg')";
}
function rollout(id){
document.getElementById(id).style.background="none";
}
function display_page2(){
 document.getElementById("page1").style.display="none";
 document.getElementById("page3").style.display="none";
 document.getElementById("page2").style.display="block";
}
function display_page1(){
 document.getElementById("page1").style.display="block";
 document.getElementById("page3").style.display="none";
 document.getElementById("page2").style.display="none";
}
function display_page3(){
 document.getElementById("page1").style.display="none";
 document.getElementById("page3").style.display="block";
 document.getElementById("page2").style.display="none";
}
function display_content(id){
id_btn_display=id+"_1";
id_btn_hide=id+"_2";
document.getElementById(id).style.display="block";
document.getElementById(id_btn_display).style.display="none";
document.getElementById(id_btn_hide).style.display="block";


}

function close_task(id){
id_btn_display=id+"_1";
id_btn_hide=id+"_2";
document.getElementById(id).style.display="none";
document.getElementById(id_btn_display).style.display="block";
document.getElementById(id_btn_hide).style.display="none";
}