❗ vb08 disable a textbox>> yes or no <<

hello all i am making by autotalker better now i wanna make a choise option with 2 radiobuttons like:

radiobutten1: use 1 textbox
radiobutten2: use 2 textboxes

i got a form that has a interval in seconds some labels and 1 timer 2 buttens and 2 textboxes

now i try to find the code to disable a textbox googled like a hour but couldnt find anything can some1 help me ?

here is my coding:

Code:

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        SendKeys.Send(TextBox1.Text)
        SendKeys.Send("{enter}")
        SendKeys.Send("{enter}")

        SendKeys.Send(TextBox2.Text)
        SendKeys.Send("{enter}")
        SendKeys.Send("{enter}")
    End Sub"



Timer1.Interval = NumericUpDown1.Value * 1000

please help me !