no commit item for the item

hi,

when i am creating purchase order against accoount assingnment group "K".

i am getting an issue that it is saying

"no commit item for the item 10 and the company code 1000'

if i double click it

it is saying that no cash maangement, funds maangement is actived for the g/l account.

thanx in advance

regards,

balajit