Security Setting on web.config

[BLOEDHOND]

Hi All I have written an xml web service it works fine. My install program also works fine. The problem is that when I try and "edit" the web.config file I do not have the correct security settings on the web.config file. If I change them manually it the program works fine. Now the question. How do I go about setting security settings programmatically in .Net 2 Thanx