Simplifying Code for Drop-Down-Box in JQuery and HTML
Your code is very big and messy so this a bit tricky to really see what you are trying to do.  A few obvious things to make the code more readable:


Replace .css("display","block") with .show()
Replace .css("display","none") with .hide()
You repeat the same color changing hover over and over again.  Instead, group all your elements together and specify this function only once:

$("#containo div").hover(function() {
    $(this).css("color","#FF7722");
},function() {
    $(this).css("color","#005BAB");
});  
Do not nest hovers inside other hovers.  .hover() creates a new event handler when it is called.  If you nest them then you each time you move your mouse over the parent, the child is assigned a new event handler.  You do not want these duplicates.  Instead assign all of your events in the root level.


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This, plus a little refactoring could reduce your code considerably.  Maybe from here the code will be easier to work with so could see how to reduce it further.

$(document).ready(function() {

    function on(selector) {
        $(selector).css("color","#FF7722");
    };
    function off(selector) {
        $(selector).css("color","#005BAB");
    };

    $("#interact,#online,#tablet,#mobile,#dai,#iguide,#tv,.droptv,#vod,.dropvod")
    .hover(function(){
        on(this)
    },function(){
        off(this)
    });

    $("#tv, .droptv").hover(function(){
        $(".droptv").show();
    },function(){
        $(".droptv").hide();
    });

    $("#vod, .dropvod").hover(function(){
        on("#vod");
        $(".dropvod").show();
    },function(){
        off(".dropvod");
        $(".dropvod").hide();
    });

    $(".tab, .drop").hover(function(){
        on(".tab");
        $(".drop").show();
    },function(){
        off(".tab");
        $(".drop").hide();
    });
});