checkbox help

What i'm trying to do is, when i check a checkbox (which are the toppings for my pizza, im making online pizza menu) I want them to show up in a large label next to it. What i produce is when i select 1 check box it says " plain " in the label but when i click another it erases plain & puts " pepperoni ". Instead of erasing, i want it to be a multiline label so that it shows all the toppings i selected for that pizza.

my checkbox code is this.

Private Sub CheckBox1_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox1.CheckedChanged
CheckBox1.Enabled = False
lbltopselected.text = " plain "
End Sub

Private Sub CheckBox2_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox2.CheckedChanged
CheckBox2.Enabled = False
lbltopselected.text = " pepperoni "
End Sub

Private Sub CheckBox3_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox3.CheckedChanged
CheckBox3.Enabled = False