Private mouseEnter As Boolean = False Private Sub TextBox_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Enter Me.SelectAll() If Me.MouseButtons <> MouseButtons.None Then mouseEnter = True End If End Sub Private Sub TextBox_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseUp MyBase.SelectAll() mouseEnter = False End Sub