[XeTeX] error message

[Ruth Robbins]

hi i'm receiving and error message when the typeset (using TEXShop)  
reaches the line \begin{document}.  the help suggested that I may have  
missed a }  I have gone through everyline of code and have not found  
anything missing.  Also, I had typeset this same document before  
without making any changes to the \begin{document} line.  So I am  
rather confused as to what the problem may be.  Can anyone help me  
with this or direct me to a site that could help?

Ruth

P.S. Thanks for the help on tables a while back to those who responded.