How to pass a row of a datagriview to another form controls?

Question

I have a Main Form(MDI)that Opens a form with a button(search) and controls.This button opens a Form 2 with a datagridview.

I need to pass a row of datagridview that is in Form 2 to Form 1 controls.

I open my form 1 :  

Dim f1 As New form1
f1.MdiParent= Me
f1.Show()

I open my form 2 (search button):

Dim f2 As New form2
f2.ShowDialog()
f2.Dispose()

Form2 has a datagridview and I use the event CellContentDobleClick:

Private Sub dgv1_CellContentDoubleClick(sender As Object, e As DataGridViewCellEventArgs) Handles dgv1.CellContentDoubleClick
If (e.RowIndex = -1) Then
Return
End If
Dim dr As DataGridViewRow = dgv1.SelectedRows(0)

Me.Hide()
form1.Show()

form1.txtID.Text = dr.Cells(0).Value.ToString()
form1.txtNo.Text = dr.Cells(1).Value.ToString()
End Sub

I think that I have to access to the  instance, but I don't Know How to do it. I need a simple explanation and example. Please

Thank you!!