Visual Basic

Dim myProcess As Process() = Process.GetProcessesByName("ProcessName")<br />
            If myProcess.Length > 1 Then<br />
                MsgBox("You can only have one instance of this application running.")<br />
            End If

dim newControl as new textbox
myGroupBox.Controls.Add(newControl)

newControl.Top = oldControl.Top
newControl.Left = oldControl.Left

'in formTwo...
dim formOne as form1 = me.MdiParent

'in formTwo...
dim formOne as form1 = me.Parent

public class form1
inherits system.windows.forms.form

'--- windows generated code ---'

Friend Sub AddPanelControl(byval controlToAdd as Control, byval location as System.Drawing.Point)

   me.panel1.controls.add(controlToAdd)
   controlToAdd.Location = location

End Sub

End Class

public class form2
inherits System.Windows.Forms.Form

Private Sub button1_click(byval sender as object, byval e as buttonclickeventargs) handles button1.click

   dim formOne as form1 = me.mdiparent 'you may need to cast this return value using    ctype depending on whether or not you're using option strict on...

   dim newControl as New TextBox

   With newControl
      .Name = "myTextBox"
      .Text = ""
      'etc.
   End With

   formOne.AddPanelControl(newControl, new System.Drawing.Point(10, 10))

End Sub

End Class