If i jailbreak my iphone while it's on contract and warranty will anything happen?

Would the warranty or contract mess up and not be available or not work properly?

No, no & no.

Jailbreaking has nothing to do with warranties.

It will void your warranty, and may effect your contract.

Warranty would no longer be valid.

Answer from Apple which will almost surely filter down to service providers;

Here's the deal: Some folks have success restoring a jailbroken iPhone back to factory specs., some don't. If you fall into the later category, your warranty/support is voided.

Not all jailbroken iPhones can be restored to factory specs. That's the chance you take.