Beginner: where to declare jquery events' handler?

Beginner: where to declare jquery events' handler?

I'm starting with jQuery.
I have written the follonwing scripts in a web page:

    <a href="http://jquery.com" id="jquery">JQuery</a>
            <a id="weba" href="http://jquery.com">
            <a id="compa" href="http://jquery.com">Ordinateur</a>

   <script>
        $(document).ready(function(){
            $("a#jquery").click(function(event){
                alert("Click JQuery OK");
                event.preventDefault();
            });
        });
    </script>
   <script>
        $(document).ready(function(){
            $("a#weba").click(function(event)){
                alert("Site web");
                event.preventDefault();
            });
        });
    </script>
   <script>
        $(document).ready(function(){
            $("a#compa").click(function(event)){
                alert("Ordinateur");
                event.preventDefault();
            });
        });
    </script>

I want the 3 links to have different behaviors with a "a#'id'" selector. But here only the first link give me a msgbox not the others.

What's wrong with my code?

Thanks.

Manu.