Ruby on Rails/JQuery autoscroll for overflow:auto [duplicate]

Possible Duplicate:
Scroll to bottom of div?

I'm building a chatroom, and I would like to set it up so the scroll is always kept to the current message. For example, here is my view:

 <div id="chatWrap">
 <div id="chatLog">
<% @chatLog.each do |c| %>
    <% account = getAccountByAccountId(c.account_id) %>
    <div class="chat">
        <div class="chatUsername">
            <p><%= link_to account.username, account_path(account) %> said:</p>
        </div>
        <div class="chatMessage">
            <p><%=h c.message %></p>
        </div>
    </div>
<% end %>   
 </div>

 <textarea id="message" name="message">Type your message here and hit enter...</textarea>

 </div>

Now my css so far is as follows:

 #chatWrap {
width:800px;
margin-left:auto;
margin-right:auto;
 }

 #chatLog {
background-color:#FFFFFF;
padding:10px;
height:500px;
overflow:auto;
color:#161616;
 }

As you can see I set the overflow to auto and fixed the height of the div.

The problem is that every time I send a new message the scroll does not move to the current message.

I was wondering if there is a JQuery solution to this?

Thank you,

Brian