All tabs contents show at first time

All tabs contents show at first time

Hi,
I'm totally new to jQuery. I'd like to have your opinion about my problem.
I have a page using jQuery tabbed menu.  When the page first loads the content of all the tabs flashes for a second or two and then the selected tab is displayed. 
After that the tabs work great with smooth transitions as expected.
An external jQuery is used here and the code is:

// submenu
    $(".tab_contents").hide(); //Hide all content
    $("tr.tmenu td:first").addClass("active").show(); //Activate first tab
    $(".tab_contents:first").show(); //Show first tab content
   
    $("tr.tmenu td").click(function() {     //On Click Event
        $("tr.tmenu td").removeClass("active"); //Remove any "active" class
        $(this).addClass("active"); //Add "active" class to selected tab
        $(".tab_contents").hide(); //Hide all tab content
        var activeTab = $(this).find("a").attr("href"); //Find the rel attribute value to identify the active tab + content
        $(activeTab).fadeIn(); //Fade in the active content
        return false;
    });