Private Sub DataGridView1_CellMouseDoubleClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellMouseEventArgs)
With DataGridView1
Dim frm = New Form1
frm.sendVar = DataGridView1.Rows.Item(e.RowIndex).Cells.Item(0).Value
frm.TextBox3.Text = frm.sendVar
End With
End Sub