I am going out wih my friends tomorrow?

I WANT MY HAIR TO BE PROPER STRAIGHT ALL DAY I WILL LEAVE IN THE MORNING LIKE 8:00 AND *** BACK AT 4PM I WANT THEM DEAD STRAIGHT WHAT PRODUCT SHOULD I USE TO MAKE THEM DEAD STRAIGHT AND IF YOU DO TELL ME A PRODUCT MAKE SURE IT IS SAFE TO USE PLEASE AND CAN YOU MAKE SURE ITS EASY TO FIND I LIVE IN THE UK PLEASEEE HELP ANY HELP WILL BE REALLY APPRECIATED