Enter in Textbox reloads page instead of submitting form

[Toot]

I'm sure this is simple and there's plenty of close-but-not-quite posts...

I've got a content page containing a LoginView which has got a Textbox and Button on the AnonymousTemplate. I enter "123" in the Textbox and press enter, the page reloads (I've put a trace in the Page_Load event) and the Textbox still contains "123". If I press my Button instead of pressing enter while in the Textbox, it works as I would expect. I've tried adding

ClientScript.RegisterHiddenField("__EVENTTARGET", "MyButtonName");

(suggested instead of Page.RegisterHiddenField by my compiler) but that made no difference.
What's going on? How do I get the expected behaviour instead of a page reload?

Thanks for your help!

[Ranthalion]

I ran into this kind of problem a little while ago. Here's what I did.

I defined a javascript function to handle the keypress event in the textbox. In the function, I test if it is enter key, and if so, I set __EVENTTARGET to some value and then submit the form.

In my Page_Load in the code behind, I check the value of __EVENTTARGET, and if it is what I set it to, then I call the same function that the submit button called.

my aspx page:

<script language="javascript">
   function SubmitEnter(e)
   {
      if (e.keyCode ==13)
      {
         document.forms("Form1").__EVENTTARGET.value = "submit";
         document.forms("Form1").submit();
      }
   }
</script>

... later on...

<asp:textbox id="txtEntry" runat="server" onkeypress="SubmitEnter(event);"></asp:textbox>

In my codebehind...

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   if not (Page.IsPostBack) Then
      Call LoadStuff()  'Load drop downs and stuff...
   else
      If (Page.Request.Params("__EVENTTARGET") = "submit") then
         Call CheckInfo()  'This is the function my submit button also calls
      end if
   end if
End Sub

HTH

Ranthalion