function showTellAFriendBox()
{
    toggleDisplayOn('tell-a-friend-hover');
    showOpaqueBackgroundLayer();
}

function hideTellAFriendBox()
{
    toggleDisplayOff('tell-a-friend-hover');
    showOpaqueBackgroundLayer();
}

function showHoverBox()
{
    toggleDisplayOn('hover-box');
    showOpaqueBackgroundLayer();
}

function hideHoverBox()
{
    toggleDisplayOff('hover-box');
    hideOpaqueBackgroundLayer();
}

function showOpaqueBackgroundLayer()
{
    toggleDisplayOn('opaque-div-layer');
}

function hideOpaqueBackgroundLayer()
{
    toggleDisplayOff('opaque-div-layer');
}

function showLayer(elementId)
{
    document.getElementById(elementId).style.display = 'block';
}

function hideLayer(elementId)
{
    document.getElementById(elementId).style.display = 'none';
}