Getting a value that follows string.find()

[englishkevin110 at gmail.com]

I know the title doesn't make much sense, but I didnt know how to explain my problem.

Anywho, I've opened a page's source in URLLIB
starturlsource = starturlopen.read()
string.find(starturlsource, '<a href="/profile.php?id=')
And I used string.find to find a specific area in the page's source.
I want to store what comes after ?id= in a variable.
Can someone help me with this?