VS 2010 How do I have a label that counts ListBox entries?

Hi all!
Long time viewer, first time poster :)

I've just got a fairly simple coding question.
When I press the "confirm" button on my form, it creates a new entry into my ListBox.
Now, I want to have a label that will read how many entries I currently have in this ListBox.
It should also be able to count not only when an entry is added, but when it is deleted.
I've got a rough idea however it's not working. Could anyone help me in this circumstance?

Thanks in advanced,
Hitman3095