Resetting Textbox.Text in UserControl
<pre><code>&lt;%@ Control Language="C#" AutoEventWireup="true" CodeBehind="ChatUserControl.ascx.cs"
    Inherits="MetamorphismApp.ChatUserControl" %&gt;

&lt;asp:Timer ID="timer1" runat="server" OnTick="timer1_Tick" Interval="5000"&gt;
&lt;/asp:Timer&gt;
&lt;div id="divChatWindow" class="clChatWindow"&gt;
    &lt;div&gt;
        &lt;asp:Label runat="server" Text='&lt;%# Eval("username") %&gt;' class="divHeader" ID="lblChatFriend"&gt;&lt;/asp:Label&gt;
        &lt;asp:Image ID="imgFriend" runat="server" CssClass="classFriendImage" /&gt;
        &lt;asp:LinkButton ID="lbClose" runat="server" CommandName="Close" CssClass="lbClose"
            OnClick="lbClose_Click"&gt;Close&lt;/asp:LinkButton&gt;&lt;/div&gt;
    &lt;div class="chatText" id="idChatText" runat="server"&gt;
        &lt;asp:UpdatePanel ID="UpdatePanel" runat="server"&gt;
            &lt;Triggers&gt;
                &lt;asp:AsyncPostBackTrigger ControlID="timer1" EventName="Tick" /&gt;
                &lt;asp:AsyncPostBackTrigger ControlID="btnSendChat" EventName="Click" /&gt;
            &lt;/Triggers&gt;
            &lt;ContentTemplate&gt;
                &lt;asp:Repeater runat="server" ID="rpChatMessages"&gt;
                    &lt;ItemTemplate&gt;
                        &lt;asp:Image ID="imageForFriend" runat="server" CssClass="clFriendsImage" ImageUrl='&lt;%# "HttpImageHandler.jpg?username=" +  DataBinder.Eval(Container.DataItem,"fromusername").ToString() %&gt;' /&gt;
                        &lt;asp:Label ID="chatMessage" runat="server" Text='&lt;%# Eval("Message") %&gt;'&gt;&lt;/asp:Label&gt;
                        &lt;br&gt;
                    &lt;/ItemTemplate&gt;
                &lt;/asp:Repeater&gt;
            &lt;/ContentTemplate&gt;
        &lt;/asp:UpdatePanel&gt;
    &lt;/div&gt;
    &lt;asp:TextBox ID="txtChatMessage" runat="server" Width="142px" CssClass="clChatMessage" EnableViewState="true"
        TextMode="MultiLine"&gt;&lt;/asp:TextBox&gt;
    &lt;asp:LinkButton ID="btnSendChat" runat="server" CommandName="Insert" CommandArgument='&lt;%# Eval("username") %&gt;'
        OnClick="btnSendChat_Click"&gt;Send&lt;/asp:LinkButton&gt;

&lt;/div&gt;


protected void btnSendChat_Click(object sender, EventArgs e)
        {            
            string username = lblChatFriend.Text;
            ucc.InsertMessage(Session["username"].ToString(), username, txtChatMessage.Text);
            txtChatMessage.Text = "";
        }
</code></pre>

<p>txtChatMessage does not become blank when btnSendChat_Click event handler is called</p>
