I have seen that after flashing a phone the line 1 and line 2 option on the phone dissaperes ....I am talking of the option That if u press the ' # ' button for a while the operator line 1 changes into line 2.....This option dissaperes after flashing....WHY ????

I discovered a new thing that when i flashed the phone after that if i go into MENU > SETTINGS > and then there are all total 8 options...But the funny thing about it is that after 1 2 3 4 5 there is no no. 6 option ..and then again 7 8......
Please explain what may be the problem......