Sizing Textbox with form size ? [Resolved]

I have a textbox and when i run my code it runs but not exact, the width is like 2 - 4 units off unless i subtract it manaully in code. Is there another method that is exact ?

heres my current code

VB Code:

Protected Overrides Sub OnResize(ByVal e As System.EventArgs)
        rt.Width = Me.Width 
        rt.Height = Me.Height
 
    End Sub

just a note:
I just started .net recently so im still learning.

Do you want the textbox to be the same size as the form? If you, just set it to fill in the Dock property

Thanks alot