How Do You Derive Equations for a Mass-Spring System?

[darkecho2]

I need help in finding the equations that describe this system.

http://img530.imageshack.us/img530/2584/44567537be2.jpg

Any help will be appreciated.
Thank you,

Kfir

 

[J77]

You need to show some working/ideas of equations to use...

 

[darkecho2]

If I knew,I would have added them.
I don't have an examle of a solution.
Sorry.

 

[J77]

Look up something on eg. "Lagrange's equations".