C# - Continuously Updating Chat Messages?

I'm creating a very simple chat application. It has an ASP.NET web page as front-end and a WCF service as back-end for storing the messages to a database.Everything works great except one thing; when Browser A enters a chat message I want Browser B to see the message as soon as possible (yeah, I know, that's the purpose of a chat).What I've done so far is to setup a trigger within the UpdatePanel, like this:

<Triggers>
<asp:AsyncPostBackTrigger ControlID="chatTimer" EventName="Tick" />
</Triggers>

which uses a timer:

<asp:Timer ID="chatTimer" runat="server" OnTick="chatTimer_Tick" Interval="1000" />

Is this the best approach or is there a better, yet simple, way to accomplish updating of messages. One drawback with this solution is that the textbox used to enter chat messages loses focus every time the Tick event runs.