Hey guys i'm stuck on the missile base where selphie wants to help out..

Didnt you ask something similar like this?
You are required to talk to the half-dead galbaldian soldier and get the password for the machine that requires to set the error ratio.

When you enter the missile base head left and go through the door. Theres a save point right in front of you and two doors to you left (probably the part your talking about). Examine the panel between the two doors to open ther one on the left. Head forward and choose to walk by casually. Run across the walkway on the next screen and down the stairs. Another save point here. Speak to the two men and take the lower left exit
Beside the stairs. You'll find a draw point here containing Blind and a
Couple of guards standing around minding their own business. Speak to the
Guard standing on the left of the other one. After speaking with him go back
Up one screen, then through the door leading up. Speak to the man at the
Top and tell him the other crew says to go on ahead. After speaking with him
Return to the other crew and give them the news. Return once again back to
The room being guarded by the soldier who commented on your walking style. Talk to him to get him to leave his position. Examine the control panel in
The room and just hit whatever. Once the lights are out, leave the room. Try
To talk your way out of the situation by telling them you were just about to
Go make the call. Go back down the stairs again and approach the door. When
The guy comes out, agree to give him a hand with the thing. Check the left
Part of this room beside one of the large missile silos to find an invisible
Draw point for Full-Life. Now get in between the two guys and then tap square
Repeatedly to move the launcher. Finally leave this room and examine the
Computer terminal on the right side of the door. Choose the Target option and
Then set error ratio. Next choose data upload and then exit the program. After this head upstairs and it's time to cause a ruckus.