Identify textboxes through looping statement

Looping objects are different from other datatype.
This method of looping statement are used to identify each object as any kind of object based in a form

a very simple code to track each object and manipulate each data as you need.

Dim ctrl As Control
 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim ctrl As Control
        For Each ctrl In Panel1.Controls
            If (ctrl.GetType() Is GetType(TextBox)) Then
                Dim txt As TextBox = CType(ctrl, TextBox)
                'txt.BackColor = Color.LightYellow
                txtEmplty(txt)
            End If
        Next
    End Sub
Private Function txtEmplty(ByVal objTxt As Object)
        Select Case objTxt.Text
            Case Is = "ServerName"
                txtServer.ForeColor = Color.Red
            Case Is = "UserName"
                txtUser.ForeColor = Color.Red
            Case Is = "PassWord"
                txtPass.ForeColor = Color.Red
            Case Is = "Port"
                txtPort.ForeColor = Color.Red
        End Select
        Return 0
    End Function