Getting a 18 month old to listen

please tell me how to correct a 18 month old boy. He cried if he doesn't get his way.
I have tried to distract him to another task but he seems to go back to what he wants to do.

I havent got any children of my own, but my fellas mother has a 2year old who acts the same way, the way we deal with this is when he is looking for something that he wants but is not allowed we turn or head and dont listen to him, he cries for about 2 minutes and then he starts to play with something else. (I think it just something all children go though at that stage they get jealous of other children and think they can have anything they want)

little ones just dont have the attention span to remember sometimes. With my kids it sometimes takes 2-3 weeks to get it that they cant have or do something they want. And yes they will cry but it goes away quick and they will still love you even if they had a screaming tantrum because you wont let them play with the dvd player.just pick a method and set of rules and stick to it. Patience and consistency are really needed when coping with toddlers.