How to Use replace for Spcial characters in Pig

[Sanjeev Shrivastava]

Hi
I am trying to use REPLACE function in PIG to clean the string  in following 
way..

REPLACE(REPLACE(REPLACE('string','.',' '),'-',' '),'  ',' ')

So if string has got . or - or  spaces , it removes it...

However when I do it using PIG it makes the string as null and does not give me 
result(because of special character?)


Any suggestions from brains out there?

Thanks
Sanjeev