function levelClick(level_number)
{
    var level_head;
    var level_body;
    var level_body_1;
    var level_body_2;
    var level_body_3;
    var level_body_4;
    var level_body_5;
    var level_body_6;
    
    level_head = document.getElementById("level_head");
    level_body = document.getElementById("level_body");
    level_body_1 = document.getElementById("level1_content");
    level_body_2 = document.getElementById("level2_content");
    level_body_3 = document.getElementById("level3_content");
    level_body_4 = document.getElementById("level4_content");
    level_body_5 = document.getElementById("level5_content");
    level_body_6 = document.getElementById("level6_content");
    
    switch(level_number)
    {
        case 1:
            level_head.style.backgroundImage = "url(Images/v1/about/talknow.gif)";
            level_body_1.style.display = "block";
            level_body_2.style.display = "none";
            level_body_3.style.display = "none";
            level_body_4.style.display = "none";
            level_body_5.style.display = "none";
            level_body_6.style.display = "none";
            break;
        case 2:
            level_head.style.backgroundImage = "url(Images/v1/about/talkmore.gif)";
            level_body_1.style.display = "none";
            level_body_2.style.display = "block";
            level_body_3.style.display = "none";
            level_body_4.style.display = "none";
            level_body_5.style.display = "none";
            level_body_6.style.display = "none";
            break;
        case 3:
            level_head.style.backgroundImage = "url(Images/v1/about/talkthetalk.gif)";
            level_body_1.style.display = "none";
            level_body_2.style.display = "none";
            level_body_3.style.display = "block";
            level_body_4.style.display = "none";
            level_body_5.style.display = "none";
            level_body_6.style.display = "none";
            break;
        case 4:
            level_head.style.backgroundImage = "url(Images/v1/about/worldtalk.gif)";
            level_body_1.style.display = "none";
            level_body_2.style.display = "none";
            level_body_3.style.display = "none";
            level_body_4.style.display = "block";
            level_body_5.style.display = "none";
            level_body_6.style.display = "none";
            break;
        case 5:
            level_head.style.backgroundImage = "url(Images/v1/about/talkbusiness.gif)";
            level_body_1.style.display = "none";
            level_body_2.style.display = "none";
            level_body_3.style.display = "none";
            level_body_4.style.display = "none";
            level_body_5.style.display = "block";
            level_body_6.style.display = "none";
            break;
        case 6:
            level_head.style.backgroundImage = "url(Images/v1/about/vocabuilder.gif)";
            level_body_1.style.display = "none";
            level_body_2.style.display = "none";
            level_body_3.style.display = "none";
            level_body_4.style.display = "none";
            level_body_5.style.display = "none";
            level_body_6.style.display = "block";
            break;
    }
}