[RESOLVED] Web browser control Problem?

[danasegarane]

I am using a web browser control to autologin to a webpage. When I intially gives the username and password,it works well.
And for the second time it is not taking the username and password from the code.I dont know where it take from I get the err messeag as attached here.
And the code is

wb1.Navigate "http://www.netwealth.com.au/"
    Do Until wb1.ReadyState = READYSTATE_COMPLETE
        DoEvents
    Loop
wb1.Document.login.username.Value = "usernamehere"
wb1.Document.login.password.Value = "mypassword"
wb1.Document.login.submit