递归验证用户输入有关问题

	function checkenter($canshu){
	        //验证输入
		$obj = new base($canshu);
		$re1 = $obj->list_tables($canshu);
			
		//如果验证不通过
                if($re1 === false){
			echo "The '$canshu' was not found, Please input again \n";
			//再次要求输入
                        $canagin = enter();
			//递归验证
                        checkenter($canagin);
		}
		return $canshu;
		
	}
       $result = checkenter($canshu);
	var_dump( $result);