InnerHtml -- Submitting form.

I'm working on a easy-login client, but I can't hit submit for the love of god.. my code looks a bit like this:
Me.WebBrowser1.Document.All("Username").SetAttribute("value", txtUser)
Me.WebBrowser1.Document.All("Password").SetAttribute("value", txtPw)
Me.WebBrowser1.Document.Forms(0).InvokeMember("Login")

I'm pretty certain I have the name right for login.. The User and password fill in wonderfully.. Any suggestions? (I've tried this on other web forms and I couldn't hit submit on them, either)

Already couple of post regarding the autologin posted here, search it...

If you can't find provide the source page of your login client web!