Bandwidth Load Balancing

Hi,
I am using MT 2.9.29.

We have 2 x 2Mbps Leased line. (Internet Incoming)

Now i want Load Balancing for both lines for my network request.
The MT shouls manage both the leased line automatic.

Both lines are from different ISP.

Pl explain me how to configure.

follow the link and go ahead
http://www.mikrotik.com/testdocs/ros/2.9/ip/route.php