How do I use bvp4c to solve two ODEs with periodic boundary conditions.

Hi. I have two ODEs of the form:

y1' = f(y1,y2,x,lambda)

y2' = g(y1,y2,x,lambda)

where lambda is an unknown parameter.

I wish to solve these subject to the boundary conditions:

y1(0) = y1(2pi)

y2(0) = y2(2pi)

using bvp4c on the interval 0 to 2pi. Can someone provide me with the structure of the best way do do this?

Than you very much,

Dave