Do NOT tell them you have Asperger's Syndrome.
If the business knows you have any kind of psychiatric disorder they will NOT, I repeat, will NOT hire you. The business world is very conservative and has a limited understanding of psychiatric disorders. The general assumption will be that if you have any kind of behavioral or psychiatric disorder it may cause you to become incompetent and/or you may have problems on the job. Not saying you will, just saying that this is what your potential employer would think.
Advice: Act normal, don't mention anything "different" about you that could be perceived as a negative (trust me, Asperger's is one of those things). On the job keep it on a stringent "Don't Ask, Don't Tell" basis. If it does cause problems for you at work talk it over with a psychiatrist and (as one person suggested) human resoruces, but do not ever let your boss know about it.