Web to Lead Problem

Web to Lead Problem

I have embedded the code, but then altered some of the pick list options in the fields.
Emails are not arriving from our website.
If we untick a pick list field, will this stop this form working on the website?
If we change pick list items will this stop this form working on the website?
If we make any changes to the pick list fields, do we have to generate new code and replace existing code on the website?