Went to get my oil changed and the guy asked: 10W30 or 5W30

I put in 10W30. The Manual says 5W30.

What now?
Derek


1999 Contour Sport SE (Black)
Duratech V6 MTX
Brullen Cat-Back Exhaust *LOUD*
S&B Powerstack Filter
Eurolite Xenon bulbs