Convert string to datetime

hi there, hope in your help.

I need convert string to datetime format AM or PM.

I tried this, buy the output in null, why?

mysql> SELECT
	STR_TO_DATE(
		'16/02/2013-04:35:32 p.m.',
		'%d/%m/%Y-%H:%i:%s %r'
	) AS NewDate;
+---------+
| NewDate |
+---------+
| NULL    |
+---------+
1 row in set

mysql> 

change ‘p.m.’ to ‘PM’
change %H to %h
change %r to %p

thanks