How to: make a user press a combination of buttons to play an animation. for example door open.

How would i make a number combination lock, i know i need the buttons and a script but dont know what script.

Anyone got one that they can share?

if you needed just a combination of buttons you could use:

if( Input.GetKey(KeyCode.O) && Input.GetKey(KeyCode.P) && Input.GetKey(KeyCode.E) && Input.GetKey(KeyCode.N) /*... and so on */)
{
Animation.Play( YourAnimation );
}

Based on the title of your question this might be what you are looking for, do you have anything more specific?