function IsThisBrowserIE6() {
    if (typeof document.body.style.maxHeight != "undefined") {
      return false;
    } else {
      return true;
    }
}

jQuery(document).ready(function() {
    jQuery('div#header-right img, div#header-left img').click(function(){
        
        // get img id
        if (IsThisBrowserIE6()) {
            var active_img = extractActiveImg( jQuery(this).css('filter') );
            var active_tab = jQuery(this).attr('id');
        }
        else {
            var active_img = extractActiveImg( jQuery(this).attr('src') );
            var active_tab = jQuery(this).attr('id');
        }

        // activate this tab
        activateColormix(active_img, active_tab);
    });
    
    function extractActiveImg( img_src ) {
        var regex = new RegExp('-tab-(\\d)');
        var results = regex.exec( img_src );
        var active_img = results[1];

        return active_img;
    }
    
    function activateColormix( active_img, active_tab ) {
        // get the current active id
        var c_active_img = extractActiveImg( jQuery('div#header-middle img').attr('src') );

        // hide the current active one
        jQuery('div#header-middle').slideUp('medium');
        
        // switch images
        var src_middle_image  = '../_images/header-' + colorcode + '-tab-' + active_img   + '.jpg';
        var src_sidebar_image = '../_images/_' + language + '/header-tab-' + c_active_img + '.png';
        jQuery('div#header-middle img').attr('src',src_middle_image);
        jQuery('div#header-middle').css('background-image','url(../_images/_'+language+'/bg-header-tab-'+active_img+'.png)');
        
        // change tabs
        

        if (IsThisBrowserIE6()) {
            jQuery('img#'+active_tab).css('filter','progid:DXImageTransform.Microsoft.AlphaImageLoader(src="'+src_sidebar_image+'", sizingMethod="scale")');
        }
        else {
            jQuery('img#'+active_tab).attr('src',src_sidebar_image);
        }




        // show middle tab
        jQuery('div#header-middle').slideDown('medium');
    }
});