When pressing a key, play an animation, when pressing same key, play different animation?

I need to play an animation every time you press the ‘s’ key, but I need to play 4 animations using the same ‘s’ key. How can you do this? This is what I have so far:

function Update()
{
if (Input.GetKeyDown("s"))
 {
 animation.Play();
 }
}

This works fine, but I need it so I can play three more animations using the same key. How?

Thanks guys, any help is appreciated

Have a variable that is set to a value depending on how many times the key has been pressed. Think an into should work in this example.

var currentState : int = 0; 

//if (Input.GetKeyDown("s"))
if(currentState == 0){
animation.Play(); //Set to correct annimation
currentState = 1;
} else if(currentState == 1){
animation.Play();
currentState = 2;
}else if(currentState == 2){
animation.Play();
currentState = 3;
}else if(currentState == 3){
animation.Play();
currentState = 0;
}

This code is demonstration only. But I think you get the idea.