Sum negative values in Money column

I'm trying to sum two columns, and subtract the two sums to get a balance amount of two columns. But I'm getting the same output for both queries even though I know there are negative values. I need to exclude those negative values in the query.

SELECT SUM(ReceiptAmt) - SUM(BalanceAmt) FROM Receipt 
SELECT SUM(ReceiptAmt) - SUM(BalanceAmt) FROM Receipt WHERE ReceiptAmt > 0.00

Any ideas on how to exclude the negative values? Or even a different approach to this.

From stackoverflow

• Should the BalanceAmt be in the where clause also?

  WHERE ReceiptAmt > 0.00 
        AND BalanceAmt > 0.00
  

• this may be what you're after:

  SELECT SUM(case when ReceiptAmt<0 then 0 else ReceiptAmt end) - SUM(case when BalanceAmt<0 then 0 else BalanceAmt end) FROM Receipt

  Tim Meers : This works by replacing the values rather than adding a WHERE clause. It also helped me identify that it's my problem. The negative values are negative the same is *both* columns! So of course it's going to return the same result frmo both of my queries. Thanks for the help.