>I'm not familiar with (negative) cost margins, but generally speaking I would test for the relative cost/price and use an appropriate formula. E.g.:

>
>IF tnCost <= tnPrice
>    lnMargin = ROUND((1-(tnCost/tnPrice)) * 100,1)
>ELSE
>*   Put a suitable formula here
>*   ( or tell them negative margins are not allowed? )
>ENDIF

I already figured this out by myself.  What I need is the forumla or algorythm to do the negative calculations.  I can't disallow the negative.