var actual_page, prev_page, prev_prev_page, prev_prev_prev_page;

function load_page( page )
{
    //CONTENT
    var req1= null;
    try
    {
        req1 = new XMLHttpRequest();
    }
    catch(ms)
    {
        try
        {
            req1 = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (nonms)
        {
            try
            {
                req1 = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (failed)
            {
                req1 = null;
            }
        }
    }
    if (req1 == null)
    {
        alert("Error creating request object!");
    }
    req1.open("GET", 'ajax/content.php?page=' + page, true);
    req1.onreadystatechange = function()
    {
        switch(req1.readyState)
        {
            case 4:
                if(req1.status!=200)
                {
                    alert("Fehler:"+req1.status);
                }
                else
                {
                    document.getElementById('content').innerHTML = req1.responseText;
                    if( page == 'manage_home' || page == 'manage_ueber_uns' || page == 'manage_vereinsgeschichte' || page == 'manage_shop' || page == 'manage_kontakt' )
                    {
                        setup();
                    }
                    else if( page == 'kontakt' )
                    {
                        initialize( 'Birmenstorf, Baden, Aargau' );
                    }
                    else if( page.slice( 0, 14 ) == 'veranstaltung_' )
                    {
                        initialize( document.getElementById('location').innerHTML );
                    }
                }
            break;
    
            default:
                return false;
            break;
        }
    };
    req1.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    req1.send(null);
    
    //LOGO
    var req2 = null;
    try
    {
        req2 = new XMLHttpRequest();
    }
    catch(ms)
    {
        try
        {
            req2 = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (nonms)
        {
            try
            {
                req2 = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (failed)
            {
                req2 = null;
            }
        }
    }
    if (req2 == null)
    {
        alert("Error creating request object!");
    }
    req2.open("GET", 'ajax/logo.php?page=' + page, true);
    req2.onreadystatechange = function()
    {
        switch(req2.readyState)
        {
            case 4:
                if(req2.status!=200)
                {
                    alert("Fehler:"+req2.status);
                }
                else
                {
                    document.getElementById('logo').innerHTML = req2.responseText;
                }
            break;

            default:
                return false;
            break;
        }
    };
    req2.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    req2.send(null);
    
    //MENU
    var req3 = null;
    try
    {
        req3 = new XMLHttpRequest();
    }
    catch(ms)
    {
        try
        {
            req3 = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (nonms)
        {
            try
            {
                req3 = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (failed)
            {
                req3 = null;
            }
        }
    }
    if (req3 == null)
    {
        alert("Error creating request object!");
    }
    req3.open("GET", 'ajax/menu.php?page=' + page, true);
    req3.onreadystatechange = function()
    {
        switch(req3.readyState)
        {
            case 4:
                if(req3.status!=200)
                {
                    alert("Fehler:"+req3.status);
                }
                else
                {
                    document.getElementById('menu').innerHTML = req3.responseText;
                }
            break;

            default:
                return false;
            break;
        }
    };
    req3.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    req3.send(null);
    
    //SIDEBAR
    var req4 = null;
    try
    {
        req4 = new XMLHttpRequest();
    }
    catch(ms)
    {
        try
        {
            req4 = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (nonms)
        {
            try
            {
                req4 = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (failed)
            {
                req4 = null;
            }
        }
    }
    if (req4 == null)
    {
        alert("Error creating request object!");
    }
    req4.open("GET", 'ajax/sidebar.php?page=' + page, true);
    req4.onreadystatechange = function()
    {
        switch(req4.readyState)
        {
            case 4:
                if(req4.status!=200)
                {
                    alert("Fehler:"+req4.status);
                }
                else
                {
                    document.getElementById('sidebar').innerHTML = req4.responseText;
                }
            break;

            default:
                return false;
            break;
        }
    };
    req4.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    req4.send(null);
    
    //FOOTER
    var req5 = null;
    try
    {
        req5 = new XMLHttpRequest();
    }
    catch(ms)
    {
        try
        {
            req5 = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (nonms)
        {
            try
            {
                req5 = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (failed)
            {
                req5 = null;
            }
        }
    }
    if (req5 == null)
    {
        alert("Error creating request object!");
    }
    req5.open("GET", 'ajax/footer.php?page=' + page, true);
    req5.onreadystatechange = function()
    {
        switch(req5.readyState)
        {
            case 4:
                if(req5.status!=200)
                {
                    alert("Fehler:"+req5.status);
                }
                else
                {
                    document.getElementById('footer_menu').innerHTML = req5.responseText;
                }
            break;

            default:
                return false;
            break;
        }
    };
    req5.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    req5.send(null);
    
    if( page == prev_page )
    {
        actual_page = page;
        prev_page = prev_prev_page;
        prev_prev_page = prev_prev_prev_page;
        prev_prev_prev_page = '';
    }
    else
    {
        prev_prev_prev_page = prev_prev_page;
        prev_prev_page = prev_page;
        prev_page = actual_page;
        actual_page = page;
    }
}
function reload_page()
{
    load_page( actual_page );
}
function back_page()
{
    load_page( prev_page );
}