reg function module POSTING_INTERFACE_CLEARING

Dear experts,

I have a requirement in tcode FB05(Posting with clearing: Initial screen). In that i need to select the radio button 'Transfer Posting with Clearing'. I dont know exactly what happens here. I have to use function module POSTING_INTERFACE_CLEARING to post and clear the document. Can anybody tell me what this function module will do and by guiding me in this regard. Kindly help me in giving sample code as to how to handle this.

thks in advance,

ram