Anuradha ...
It is very simple ...
On your Main form (frmSignIn) whatever control you are using to run the validate code, just put something like this
Private Sub Command1_Click()
Load Form2 'Loads form to memory
Unload Me 'Unloads form 1 to clear memory
Form2.Show 'Makes form 2 visible
End Sub
You could also use the Hide method on form 1, but since it is a log-in form, unload is better.
HTH
Michael