Load balance two wan links

Dear all,
I have two Internet connections.i want to load balance on these two links.
I means that when two links are ok,our lan traffic goes from two links and when one of these links fail,it automatically send traffic via another link.
Can you help me?
I want any documents about these feature on mikrotik.
i apologize for my bad english.

mlppp or ecmp

both described in the wiki

Thanks a lot for your reply.
Could you describe clearly or give me any documentation about this?

hello ashkan61:
The balance can real be doen in some ways.The key point just is using.It’s mean that,what’s is balancing for? To get a biger bandwidth? or for faster? or foe eazy to manane? :laughing:
You can mark the connection and route by /ip firewall man.
If you wanna some help in this ,you can mail to me hillzen@163.com. I’ll do my best for help you

Hillzen

http://www.mikrotik.com/testdocs/ros/3.0/ip/route.php

http://wiki.mikrotik.com/wiki/ECMP_Failover_Script

i am recommending this tutorial from wiki:
http://wiki.mikrotik.com/wiki/Load_Balancing_Persistent