Hey. My hair is blond and not rele long and they are all over the place.. when I straiten them and walk outside they get curly gain.. what should I use to make them straight and that they wouldn't look messy most of the time?

Your hair is a collective item, so you can't really refer to your hair as 'they'. That infers it isn't really a part of you, lovey. You have to buy a hair relaxant that you use every time you shampoo. The humidity is doing that and possibly your hair isn't thick enough to get over it. You need a good conditioner, and don't spare the money if you want to be happy with your hair. I really enjoy using ProV products.

Tick

You could try Bedheads Control Freak extra straight
bed heads - Compare Prices and Buy bed heads at Shopping.com

Many local stores sell it.

My hairs naturally straight, But when I straighten it with a hair straightener my hair doesn't stay straight for long, it starts to curl a tiny bit at the tips.

So I use a blow dryer and a brush, it does heaps better and last longer. Aslong as yah don't get it wet :)
& Bedheads Control Freak extra straight; works good as well.