how to prevent cross site scripting

Question

hi,

 i am developing an web application to validate credit card..
 
i need to protect credit card information from cross site scripting.. what are all the possible ways

to protect from CXX.
 
can i use encryption/decryption...if it is give me a sample how to use ...

expecting positive note...

Thanks in advance for you valuable information..


regards,
senthil kumar.