Reading F-keys on a Text box

Does anyone know how to capture the f-keys in a Textbox

I have tried the keypress event but the event does not fire when pressing any f-keys ie : F2

StaticInc here is a cut and paste example of capturing the F4 key top open another form. This should be self explanatory but if you need more help just post back.

VB Code:

Public Sub capKeyDown_KeyDown(ByVal sender As Object, _
        ByVal e As KeyEventArgs)
 
        Select Case e.KeyCode
            Case Keys.F4
                If sender Is txtEmp Then
                    Dim newForm As New frmShowEmp
                    newForm.ShowDialog()
                ElseIf sender Is txtJobNumber Then
                    Dim newForm As New frmShowJob
                    newForm.ShowDialog()
                End If
        End Select
 
    End Sub
 
    Private Sub txtEmp_KeyDown(ByVal sender As Object, _
        ByVal e As System.Windows.Forms.KeyEventArgs) _
        Handles txtEmp.KeyDown
 
        capKeyDown_KeyDown(txtEmp, e)
 
    End Sub