Footstep Script Not working

I’m trying to get a footstep sound to play when the player walks. I’m using the Indie version on unity. I have this java script placed on the player:
#pragma strict

//Create a variable to tell whether the player is walking or not
var isPlayerWalking = false;
var TileSound : AudioClip;
var TileTimer : float = 0;
var TileCooler : float = 0.8;
var WaterSound : AudioClip;
var WaterTimer : float = 0;
var WaterCooler : float = 0.8;

function Update(){
    //Check to see if the player is walking by checking for input from the walking keys
    if(Input.GetKeyDown("a") || Input.GetKeyDown("w") || Input.GetKeyDown("s") || Input.GetKeyDown("d")){
       //if those keys are pressed, the player must be walking...
       isPlayerWalking = true;
    }
    else{
       //if those keys aren't presesd, the player can't be walking.....
       isPlayerWalking = false;
    }
}

	if (TileTimer > 0){
		TileTimer -= Time.deltaTime;
	
	}
	
	if (TileTimer < 0){
		TileTimer = 0;
	}
	
function PlayTileSound (){
	  if(TileTimer == 0){
         audio.PlayOneShot(TileSound);
      }
}

function PlayWaterSound (){
	  if(WaterTimer == 0){
         audio.PlayOneShot(WaterSound);
      }
}

function OnCollisionEnter(collision : Collision){
    //Check if the player is walking...
    if(isPlayerWalking == true){
       //If the player is walking, check what sort of ground they're walking on, and then play that sound...
       if(collision.gameObject.tag == "floorTile"){
       	PlayTileSound ();
       }
    }
         
       else if(collision.gameObject.tag == "floorWater"){
         PlayWaterSound ();
       }
}

The character is standing on a floor (cube) with the correct “floorTile” tag. I have also checked and entered the sounds into the script in the inspector. I don’t really know what to do, so any help would be appreciated.

I think you want to create an animation event that calls a step event function in your script.
http://docs.unity3d.com/Documentation/Components/animeditor-AnimationEvents.html

Considering that your step sound is a single sound, just “pock”. Add a little silent to the end of it (using Audacity or other sound software). Then just play in a loop.

var sound:AudioClip;
function Start(){
  audio.loop = true;
  audio.playOnAwake=false;
}

function Update(){
  if(Input.GetKey(KeyCode.Space)){
    if(!audio.isPlaying)audio.Play();
  }else if(Input.GetKeyUp(KeyCode.Space))audio.Stop();
}

Note that what I do in the start can be done in the Inspector.

Your issue is that you might have to play a little with the speed of the file to make it match the steps.