hi,
on your proposal or contract put a space for a name of the person or persons authorized to make changes.

i remember one time the formeman on the job did not know his name was the only person authorized to make a change..he agreed with the owner to do some extra work...the foremans company was P.O.'ed because they forgot they wrote his name in...the foreman never told the boss about the changes..they tried to balk but my lawyer convinced them to pay as agreed...

get it in writng my friend..at least you will have that..a businessman always gets it in writing..

mustang