Chich funcation can give me the left time of burning?

I have search in the neroapi.h to find the funcation that that can get the
burn time left;
for example :it can tell me when the burn will complete?
how much time leave?
Then I can tell the user to wait until the burn complete!
any answer will be greate,

There is no such function. What you can do instead is calculate the estimate of the remaining time as a proportion of the current percent completed (as received by the progress callback) and the time it took to complete. This is the best guess you can make and will usually be very close to the real thing.