might be easy

[dawgfather]

Hello there!
The problem i have might be simple, but i have given up looking.
I have a form and a textbox inside it. when i run the form and resize the form i want the textbox to resize 2. I tried form resize n this is the code i have

Private Sub frmTestPad_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Resize
txtNewDocument.Top = 100
txtNewDocument.Left = 100
txtNewDocument.Width = frmTestPad.ActiveForm.Width - 300
txtNewDocument.Height = frmTestPad.ActiveForm.Height - 600
End Sub

and this is the error i get-"Object reference not set to an instance of an object"
Thanks in advance..