function showBanner( aUrl ) {
    $( 'div#banner_overlay' ).show();
    $( 'div#banner_overlay' ).animate( {
        opacity: 0.4
    }, 800, null, $( '#banner' ).fadeIn( 'slow' ) );
    if( aUrl != null ) {
        ajax_request = $.ajax( {
            type: "GET",
            url: aUrl,
            success: function( response ) {
                $( 'div#banner_content' ).html( response );
            }
        } );
    }
    else return;
}

function closeBanner() {
    $( '#banner_overlay' ).fadeOut( 'slow' );
    $( '#banner' ).fadeOut( 'normal' );
}