[jQuery] Hot to remove or replace onclick function

[jQuery] Hot to remove or replace onclick function


HTML
-------------------------------------------------------------------------
<div id="navBox"><div></div></div>
<ul>
<li><img src="images/nav/nav_left.jpg" /></li>
<li><img src="images/nav/btn_nav1.jpg" alt="�P於新�]和�I" /></li>
<li><img src="images/nav/btn_nav2.jpg" alt="�a品展示" /></li>
<li><img src="images/nav/btn_nav3.jpg" alt="技能培��中心" /></li>
<li><img src="images/nav/btn_nav4.jpg" alt="服��" /></li>
<li><img src="images/nav/btn_nav5.jpg" alt="要��" /></li>
<li><a href="member/member_login.php"><img src="images/nav/
btn_nav6.jpg" alt="���T���^" /></a></li>
<li><img src="images/nav/btn_nav7.jpg" alt="人才招聘" /></li>
<li><img src="images/nav/nav_right.jpg" /></li>
<div class="clear"></div>
</ul>
</div>
<script language="javascript">
<!--
    $(document).ready(function()
    {
        /*navigation initial*/
        navInitial();
    });
//-->
</script>
CSS
-------------------------------------------------------------------------
#nav
{
    position:relative;
    cursor:pointer;
}
#nav img
{
    border:0px;
}
#nav ul
{
    margin:0px;
    padding:0px;
    list-style:none;
}
#nav li
{
    float:left;
}
.clear
{
    clear:both;
}
#navBox
{
    position:absolute;
    width:120px;
    height:44px;
    border:1px solid #999900;
    overflow:hidden
}
#navBox div
{
    background-color:#F8965A;
    width:120px;
    height:44px;
}
Javascript
-------------------------------------------------------------------------
function navInitial()
{
    var $nb = $('#navBox');
    $('#navBox div').css('opacity',0.3);
    $arr = {'b1':60,'b2':179,'b3':300,'b4':420,'b5':540,'b6':660,'b7':
780};
    $('#nav li:gt(0):lt(7)').mouseover(function()
    {
        var index = $('#nav li').index(this);
        var move = $arr['b'+index] + 'px';
        $nb.stop().animate({left:move});
        if(index == 6)
        {
            $nb.click(function()
            {
             window.location = 'member/member_login.php';
            });
        }
        else
        {
            $nb.click(function()
            {
                window.location = '';
            });
        }
    });
}
Hi, I use li and image for navigation button, and the script means,
when I mouse over any button, there will be a transparent div slide
above the button, but the div will cover the button, therefore, I
can't click the button to go to the page, so I write another code to
give the div a hyper link, here comes the question, some button do not
have hyper link, because it got sub menu, I will do another effect
when mouse over those button, that's mean I need to cancel if the div
move to the button which have hyper link, how to do that?