Advice on multi-checkbox form fill

[purge]

I am hoping to populate my form which using rails style checkboxes i.e

[] A (name cb[0])
[] B (name cb[1])
[] C (name cb[2])

But I can't think of an elegant way to do this using the load method, ideally I would like to populate using the following JSON

cb : [0,2] // would select checkbox A and C

Has anyone done anything similar to this or suggest the best way of going about it

Thanks in advance.

Simon.

[dboylx]

there is a thread may be helpful,
http://extjs.com/forum/showthread.php?t=5262&highlight=checkbox+multi

but this is for EXT1.X，
I haven't got any solution like that in EXT2.0.