Imports System.Drawing
Imports System.Text.RegularExpressions
Imports System.Windows.Forms

Module Module1
    Public Enum ValidationType
        MaxMin = 1
    End Enum
    Public Sub AssignValidation(ByRef CTRL As TextBox, ByVal Validation_Type As ValidationType, Min As Double, Max As Double)
        Dim txt As TextBox = CTRL

        Select Case Validation_Type
            Case ValidationType.MaxMin
                AddHandler txt.TextChanged, AddressOf MaximumMinimum
        End Select

    End Sub

    Public Sub MaximumMinimum(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim NO As TextBox = sender
        If Val(NO.Text) < Min Then
            NO.Focus()
        ElseIf Val(NO.Text) > Max Then
            NO.Focus()
        End If
    End Sub

End Module