Altering Wedding Gowns

I found a gown at a thrift store that I fell in love with and bought. It is currently too small, and while I am trying to lose weight before the wedding- it will be in November 2007- I doubt that I will make it to the required size by that date, even with diet changes and exercise. Can gowns be altered to be made larger? How much larger is possible?
Posted by Becky; updated 07/29/06