add level calculation

class/Comment.php

@@ -0,0 +1,41 @@
+<?php
+
+class Comment 
+{
+    private $id = 0;
+    private $value = array();
+    private $parent = null;
+    private $children = array();
+
+	public function __construct($id, $content) {
+		$this->id = $id;
+		$this->value = $content;
+	}
+	
+    public function addItem($obj, $key = null) {
+    }
+
+    public function deleteItem($key) {
+    }
+
+    public function getItem($key) {
+    }
+
+    public function getContent($level = 0) {
+		$comments = $this->value;
+		$comments['level'] = $level;
+		
+		foreach($this->children as $child) {
+			array_merge($comments, $child->getContent($level + 1));
+		}
+		return $comments;
+    }
+
+	public function setParent($parent) {
+		$this->parent = $parent;
+    }
+    public function addSubComment($obj) {
+		$this->children[] = $obj;
+    }
+
+}