language

	zh-cn/common_lang.php
	<?php
	return array(
		"framename"=>"蜉蝣",
		"info"=>array(
			"author"=>"志",
			"date"=>"2014-3-22",
		),
	);

	if we want to use language,there are two ways of using it.
		one. 
			we can assign it in the controller like this:
				public function lan(){
					$one=$GLOBALS['lang']['framename'];
					$this->assign('one',$one);
					$two=lang('framename');
					$this->assign('two',$two);
					$this->assign('date',lang('info','date'));
					$this->display();
				}
		two.
			we can use it directly in the template like this:
				<{$one}>

				<{$two}>

				<{$lang.framename}>
					//we didn't assign it in the controller
				<{$lang.info.author}>
				//we didn't assign it in the controller yet
				<{$date}>