Need help mr.c++ :)

Hi ePvP,
I would like to know how to run a command like this: If a packet is received (Example: U_i) It sends a packet to the server If you get to do it, I will pay you: o Thank you :D

u_i packet is sent by client ( if i am right ) so it's not needed to send it again.

Sry i don't saw that it's example.

Btw . When packet is received from server why you want to send it again?

Because ...
" u_i receive "
"c_mode send"
Thx for your answer