Getting checkboxlist values

I dynamically create a checkbox list. I then want to get the values of the checkboxes that are ticked. 
In this example it would put the text values into a textbox (I will be doing more but to get proof of concept this is ideal for testing)
I think I am close... 
The error line is - "Object reference not set to an instance of an object." on line " If CheckBoxList1.Items.FindByValue(i).Selected = True Then" 
Dim i As Integer = 0 Dim vValue As String = "test" For Each item As ListItem In CheckBoxList1.Items If item.Selected Then i += 1 If CheckBoxList1.Items.FindByValue(i).Selected = True Then '#### Do things here ' txt.Text = txt.Text & Checkbox value End If End If Next