title: Button OnClick event not firing with one textbox in the form
body: <p>I came across a very strange occurrence with ASP.NET onclick event in IE (other browsers doesn't seem to have this problem). When there is only one textbox field in a form, the onclick event doesn't fire when you enter text and hit Enter/Return. The event does fire when you click on the actual submit button. When there are two or more fields in the form, hitting Enter/Return works just fine.</p>
  
  <p>It's very strange. Thought it was something with my IE, but checked other machines, and every one of them had the same problem.</p>
  
  <p>I had setup this really simple page as a test:</p>
  
  <pre><code>&lt;%@ Page Language="C#" %&gt;
  
  &lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
  
  &lt;script runat="server"&gt;
      protected void btnSubmit_Click(object sender, EventArgs e)
      {
          Response.Write(((Button)sender).Text);
      }
  &lt;/script&gt;
  
  &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head runat="server"&gt;
      &lt;title&gt;&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;form id="form1" runat="server"&gt;
      &lt;div&gt;
      &lt;asp:TextBox ID="txtBox1" runat="server"&gt;&lt;/asp:TextBox&gt;
      &lt;asp:TextBox ID="txtBox2" runat="server" &gt;&lt;/asp:TextBox&gt;
      &lt;asp:Button ID="btnSubmit" OnClick="btnSubmit_Click" Text="Submit" runat="server" /&gt;
      &lt;/div&gt;
      &lt;/form&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>When one of the textbox is removed, the <code>btnSubmit_Click</code> event doesn't behave as expected.</p>