H4 to H1 COS approval rate and reasons for rejection if any

Hi, I am holding H4. i am planning to do H4 to H1 change of status in april 2013. please let me know the chance of approval rate. does it have any rejection rate. if so please advise the reasons for it to get rejected.

It varies from case to case as it depends upon your qualification, employer’s background/credentials/financial stability and offered H-1 position.