void OnGUI () {

    if (useTypeWriter) {
        curDialog.dialogTypeWrite = "";
        StartCoroutine(TypeText(curDialog.dialogText));
        GUILayout.Label(curDialog.dialogTypeWrite);
    }
    else {
        GUILayout.Label(curDialog.dialogText);
    }
}

IEnumerator TypeText (string s) {
    foreach (char c in s.ToCharArray()) {
        curDialog.dialogTypeWrite += c;
        yield return new WaitForSeconds (letterPause);
    }
}