[jQuery] SlideDown Issue.. help!

[for...@gmail.com]

I am new to jQuery but am using it to SlideDown a DIV element when the
a:link is clicked.

However, no matter what link i click on the page, it slides down the
div, it's as if the script has taken over every link on the page.

Here is the code:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/
jquery.min.js"></script>
        <script type="text/javascript" charset="utf-8">
    $(document).ready(function () {
        var $div = $('#alias-box');
        var height = $div.height();
        $div.hide().css({ height : 0 });

        $('a').click(function () {
            if ($div.is(':visible')) {
                $div.animate({ height: 0 }, { duration: 250, complete:
function () {
                    $div.hide();
                } });
            } else {
                $div.show().animate({ height : height }, { duration:
250 });
            }

            return false;
        });
    });
    </script>

html:

<a href="#alias-box" style="font-size:10px;">Custom Alias</a>
<div id="alias-box"><input name="new_alias" class="field_50"
type="text" /></div>

so clicking Custom Alias, drops the 'alias-box' div.

But even when i click other links such as:

<a href="contact.php">Contact</a>

it ignores going to contact.php and displays the div.

Any ideas how to fix this?