About get data from URL in FormBuilder

Hi Team
And I’m sorry I’m not good english.

I have suspect about get data from URL in FormBuilder(URL : http://wordpress.org/plugins/formbuilder/)

I want to get data from URL and select in “select dropdown” I’m not sure how to do this ?
ex
select dropdown name is “aa”
http://www.abcd.com/abcd/?aa= b
and than select “aa” = b
and b have in select dropdown list.

How to do this ?
Thank you very much and sorry for not good english.

http://wordpress.org/extend/plugins/formbuilder/