help needed on phase contrast microscope

[HaHaHa!!!!!]

I need the information on how to setup the phase contrast mode microscope
from a general type microscope. which kind of components i need to add to
it? a filter or a condenser? any information is appreciated. 

-- 
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Ziqiang Wang                       Dept. of Chemistry
wolfwang at iastate.edu               Iowa State University
tel:515-294-1127                   Ames, IA 50011  
http://www.public.iastate.edu/~wolfwang/homepage.html
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