AutoType Code: 'ToCharArray' is not a member of 'Object'

Unity Engine
1

SOLVED here is my code

var letterPause : float = 0.2;
var sound : AudioClip;

private var intDialog : int = 0;
private var word : String;

function Start () {
	word = gameObject.guiText.text;
}

function Update () {
	if(intDialog == 0){
		gameObject.guiText.text = "";
	}
	
	if(Input.GetKeyDown("space")  DialogTriggerArea.isDialoging){
		gameObject.guiText.text = "";
		intDialog++;
		ShowDialog(DialogTriggerArea.staticTalkingChar);
		TypeText();
	}
}

function ShowDialog(chara : String){
	if(chara == "Dead"){
		if(intDialog == 1){
			word = "try one try one try one try one try one";
			//gameObject.guiText.text = "try one try one try one try one try one";
		}
		
		if(intDialog == 2){
			word = "try two try two try two try two try two";
			//gameObject.guiText.text = "try two try two try two try two try two";
		}
		
		if(intDialog == 3){
			DialogTriggerArea.isDialoging = false;
			intDialog = 0;
		}
	}
}

function TypeText(){
	for(var letter in word.ToCharArray()) {
    	gameObject.guiText.text += letter;
		if(sound){
			audio.PlayOneShot(sound);
		}
		yield WaitForSeconds(letterPause);
    }       
}
2

The key to the solution being the line:

 private var word : String;