Double Entry problem

Can anyone help, please, with this problem I have just encountered in my new job? I am involved in accounts preparation.<BR><BR>A couple run a business using one bank current account for all their transactions - business and private. According to the bank statements and accounting records there is both a substantial amount of 'drawings' from the current account and, at the same time, there are no cash sales nor any evidence of cash held.<BR><BR>Some business expenditure, however, is made using cash. On analysing this I am debiting the appropriate accounts with the expenses incurred, but should I then credit 'drawings' or 'capital introduced'?<BR><BR>In other words, how will I know that cash which has been drawn from the bank account (which my knowledge of accounting tells me is 'drawings' for private use) will then not be used for business expenses?<BR><BR>Thanks very much<BR>