Debit / Credit SQL Output

I can't believe I am hung up on this one, but I just can't figure it out: I am writing an A/R accounting system for a customer. I have an AR Transactions table which basically contains an account number, a value (money) and whether it is a debit or credit. My problem is with the output. Any accounting report has the debits and credits listed in two columns. What I need is to group by account number, and put the sum(debits) and sum(credits) into two separate columns. Like this: ACCTNUM CREDITS DEBITS 12000 $100.00 $00.00 13000 $200.00 $10.00 etc. The table I am trying to run a query against looks like this: ACCTNUM VALUE TRANTYPE 12000 $50.00 Credit 12000 $50.00 Credit 13000 $100.00 Credit 13000 $100.00 Credit 13000 $10.00 Debit That nasty Ansi compliant GROUP BY clause has got me hog tied here...I have tried using the CASE statement, in which I get duplicate account numbers in the output, I have even tried a self-join which yields completely whacko results...This is so simple, does anybody have any thoughts on the SQL Query that could yield the correct results? Thanks a lot, Dan.