Button clicks when it should not

Here is the code for 3 page events  Protected Sub cmdAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdAdd.Click
lstSubgroups.Items.Add(New ListItem("Subgroup", ""))
End Sub

Protected Sub cmdRemove_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdRemove.Click
lstSubgroups.Items.Remove(lstSubgroups.SelectedItem)
End Sub

Protected Sub txtSubgroupText_TextChanged(ByVal sender As Object, Go to the complete details ...