lnMargin =ROUND((tnPrice-tnCost)/max(tnCost,tnPrice)*100,1)

>I have an application that currently uses the following formula for calculating the margin on an item sold:
>
>lnMargin = ROUND((1-(tnCost/tnPrice)) * 100,1)
>
>The problem is that we have customers entering tncost > tnPrice to create a negative margin/loss leader situation. In this case, the returns from the function are huge and cause an overflow.
>
>Can someone tell me or show me a formula that will calculate negative margins correctly?
>
>Thanks..