H1 transfer from one company to another company ..Urgent reply

Suppose , A company applied and sponsered for H1BVisa… and they terminated that person… how may days will have that person to transfer his H1 Bvisa to another Company?? Anything else have to takecare … could anyone explain about this clearly… its urgent plss

As per law, the person is supposed to leave US immediately. But I have read people mentioning that upto one week you could stay inside to get into another job (this is just info I read from various forums and websites, not sure if its practical). In such cases, if the person can identify and file an H1B petition for change of employer within few days he will be alright. He can start working for that employer as soon as he receives the receipt number from USCIS.

Its better to seek opinion from a good immigration attorney.