asking question about vb.net

Trying to wade through that is painful! Please, in future, consider using at least some punctuation...if we can;t read your question, we can't answer it. :laugh:

So, you have two forms:

Form1
   Radio button 
   Combobox

Form2
   Textbox
   DataGridView
   ButtonOne
   ButtonTwo
   OKButton

You display Form2 when the user checks RadioButton in Form1.
You enter data in the DataGridView and press OK. At this point you want to transfer information from the DataGridView to the Combobox in Form1.

There are a couple of ways to do this: If you use ShowDialog to display Form2, then just let the OK button close Form2, and pick up the new data via properties in teh Form1 code:

Dim f2 As New Form2()
f2.ShowDialog
' Use f2.Properties here to access the new values

If you use Show to display the new Form2 instance, then it's more complex: you need to create an event in Form2 which Form1 handles, and then access the Form2 properties in the handler method, using the sender parameter to identify the Form2 instance.