Urgent

I have fed the chip PIC16F877 wit a code i wish to delete but when i try n do so i receive an error message that informs me that the chip is code protected and data protected! N thats y cannot erase device.
'EPROM data is protected, reprogram entire part'

What to do??

I suggest you probably have a problem with your programmer or software? (you don't mention what either of them are), but you can't protect a 16F877 so you can't erase it. Part of the erasure process (or programming process for that matter) wipes the program and data memory, then wipes the config fuses (including the code protect fuse). It can only be done in that order, you can't easre the fuse settings without erasing all the data first (for obvious security reasons).