Handling validation controls events in code behind

 Hi,
Do u guys know if we can trap in code behind when a validation is taking place or when it s finished in code behind. I am talking about validation controls like: requiredfieldvalidator, RegularexpressionValidator..etc 
More precisely, I need to trap the event when the RegularExpressionValidator succeeds or when it fails, but I want to handle that event in code behind. Is that possible?
Thank you 
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