How to use Joomla categories as dropdown into your custom component of Joomla 2.5 or Joomla 3.3 ??

How to use Joomla categories into your custom component ??

Just using the following into your component form xml file.

<field name="category" type="Category" extension="com_content" size="40" class="inputbox" label="Select Category"
description="Category list"
required="true"
filter="safehtml" />

I hope it will save your much time......