count element content length

Hi!

Is there some method to count the elements content length and when 
for example the 20th character is met, then it would stop showing 
the rest and put ... after that. Because of my lowsy english, here
is one example:

elements content:
<Subject id="0000000002">Chattaamaan city chattiin ke klo 12</Subject>

the result should be:
<p>Chattaamaan city cha...</p>

Chears
Jarkko 

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Jarkko Moilanen         *You are wise, witty, and wonderful,      *
Researcher/ ITCM        *but you spend too much time              *
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