window.onload = Load;

function ShowMenu1() 
{
    var ul = document.getElementById('menu_content1');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) 
    {
        elements[i].style.display = "block";
    }
}

function HideMenu1() 
{
    var ul = document.getElementById('menu_content1');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) 
    {
        elements[i].style.display = "none";
    }
}

function Load() 
{
    var li = document.getElementById('main_menu1')
    li.onmouseover = ShowMenu1;
    li.onmouseout = HideMenu1;

    var li = document.getElementById('main_menu2')
    li.onmouseover = ShowMenu2;
    li.onmouseout = HideMenu2;

    var li = document.getElementById('main_menu3')
    li.onmouseover = ShowMenu3;
    li.onmouseout = HideMenu3;

    var li = document.getElementById('main_menu4')
    li.onmouseover = ShowMenu4;
    li.onmouseout = HideMenu4;
}

function ShowMenu2() 
{
    var ul = document.getElementById('menu_content2');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) 
    {
        elements[i].style.display = "block";
    }
}

function HideMenu2() 
{
    var ul = document.getElementById('menu_content2');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) 
    {
        elements[i].style.display = "none";
    }
}

function ShowMenu3() {
    var ul = document.getElementById('menu_content3');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) {
        elements[i].style.display = "block";
    }
}

function HideMenu3() {
    var ul = document.getElementById('menu_content3');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) {
        elements[i].style.display = "none";
    }
}

function ShowMenu4() {
    var ul = document.getElementById('menu_content4');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) {
        elements[i].style.display = "block";
    }
}

function HideMenu4() {
    var ul = document.getElementById('menu_content4');

    var elements = ul.getElementsByTagName('li');

    for (var i = 0; i < elements.length; i++) {
        elements[i].style.display = "none";
    }
}