var _activeTabButtonID = null;
var _activeTabContentPanelID = null;

function HandleTabButtonMouseover(tabButtonID, tabContentPanelID)
{
    SetDefaultTab();

    if ((tabButtonID != _activeTabButtonID) &&
        (tabContentPanelID != _activeTabContentPanelID))
    {
        HighlightTabButton(tabButtonID);
    }
}

function HandleTabButtonMouseout(tabButtonID, tabContentPanelID)
{
    SetDefaultTab();

    if ((tabButtonID != _activeTabButtonID) &&
        (tabContentPanelID != _activeTabContentPanelID))
    {
        HideTabContentPanel(tabContentPanelID);
        UnHighlightTabButton(tabButtonID);
        ShowTabContentPanel(_activeTabContentPanelID);
    }
}

function HandleTabButtonOnclick(tabButtonID, tabContentPanelID)
{
    if ((tabButtonID != _activeTabButtonID) &&
        (tabContentPanelID != _activeTabContentPanelID))
    {
        UnHighlightTabButton(_activeTabButtonID);
        HideTabContentPanel(_activeTabContentPanelID);
        SetActiveTab(tabButtonID, tabContentPanelID);
        HighlightTabButton(tabButtonID);
        ShowTabContentPanel(tabContentPanelID);
    }
}

function SetDefaultTab()
{
    if ((_activeTabButtonID == null) &&
        (_activeTabContentPanelID == null))
    {
        _activeTabButtonID = '_tabButton1';
        _activeTabContentPanelID = '_tabContentPanel1';
    }
}

function HighlightTabButton(tabButtonID)
{
    var tabButton = null;

    tabButton = document.getElementById(tabButtonID);

    if (tabButton != null)
    {
        tabButton.className = "TruckModelTabButtonOn";
    }
}

function UnHighlightTabButton(tabButtonID)
{
    var tabButton = null;

    tabButton = document.getElementById(tabButtonID);

    if (tabButton != null)
    {
        tabButton.className = "TruckModelTabButton";
    }
}

function ShowTabContentPanel(tabContentPanelID)
{
    var tabContentPanel = null;

    tabContentPanel = document.getElementById(tabContentPanelID);

    if (tabContentPanel != null)
    {
        tabContentPanel.className = "TruckModelTabContentPanelOn";
    }
}

function HideTabContentPanel(tabContentPanelID)
{
    var tabContentPanel = null;

    tabContentPanel = document.getElementById(tabContentPanelID);

    if (tabContentPanel != null)
    {
        tabContentPanel.className = "TruckModelTabContentPanel";
    }
}

function SetActiveTab(tabButtonID, tabContentPanelID)
{
    _activeTabButtonID = tabButtonID;
    _activeTabContentPanelID = tabContentPanelID;
}