Thank you all for the replies.

Here are the codes:
Private Sub CommandButton1_Click()
Form_Main.Hide
Form_MyForm1.Show
End Sub

The program worked fine yesterday. I made some changes today and I cannot
remember every step I did. Suddently, I got into this trouble. Strangely,
when I added a new form "UserForm1" and replaced the "Form_MyForm1.Show" with
"UserForm1.Show" above, it just worked.

I guess I probably broke a link with "Form_MyForm1.Show", but have no clue
how I did and what to do to correct it.



"Scott" wrote:

I encountered "Run-time error '9': Subscript out of range" at this line:

Form_MyForm.Show

The form is sitting there and no spelling error. Anyone can help?

Thanks.