Samsung galaxy s duos 2 problem.

[AC Question]

i've samsung galaxy s duos 2 since 2012,but i i tried to install firmware it was flashed with no problem,then i was trying to flash other firmware but odin kept showing errors so i thought it needs re partition so i've put pit file and forgot to add firmware it booted to recovery mod i pressed power button to choose reboot system now i thought it will reboot normaly but it didn't and when i connect it to pc it shows unknown device,i asked a friend of mine he said that i've deleted system place means there is no place for system atm,anyone can help me solving this?