What can i do to keep my hair straight throughout the day?

Help! my hair looks fab in the morning after ive just done it, but the min i walk out of my door, It goes frizzy and wavey.I think ive tried every trick in the book! I use Sunsilk silk and straight shampoo and conditioner, Ive got GHD straightners and put loads of hairspray and moose on my hair! please help. its so annoying