InfoPath Dev

I've built a form where a formula calculates a plus / minus amount in a field. If the difference between 2 previous fields is a positive amount I need to use one formula to create the figure that goes in the plus \ minus field but if it is a negative figure I need to use a different formula. I've tried setting the field value using one of the formulas then added a rules to say if the field value was < 0.00 to use the differnt formula. That didn' work so I tried not giving the field a value and using 2 rules - one for each condition - still doesn't work. Is this possible or is there something I'm missing?

Try deleting the value in the "default value" box and just leave the two rules to set the value.  I had something like that on my form when calculating times over a 24 or under a 24 hour period.  See if that works...

Tried leaving the default value blank and then it doesn't poplulate the necessary field at all. If I leave the default as what the field should be without the additional rules applied then it doesn't perform the calculation in the first rule but not in the second. Any further thoughts?

Don't forget that the rules are only applied after a users makes a change to THAT field.  That is probably why the formula in the default works and not the rules.  Put those two rules in the field prior to the one where you want the calculation to be and once a user puts data into it, it when then make the calculation and fill in the result field.  I am not expert by any means, but I was working some of those same issues.   

That worked. Thanks. One other question - In the properties of all these fields the totals are set to display as data type: decimal then 2 places, then under formatting - decimal places = 2 - once the form results are displayed in the sharepoint library I can't get the the columns to display only 2 decimal places and because of the calculations used in the form som of the decimal places run 6 - 8 places long. When filling out the form you only see 2 decimal places but once displayed in sharepoint it doesn't - this is likely a sharepoint issue but I can't seem to correct it. I need the Sharepoint display to be narrowed down to the 2 decimal places.Any thoughts.

I am glad that worked out for you.  As for the formating issues, I do know there is a difference in the display format and the storage format.  You are probably going to have to dig into the library design mode and see what the format of the actual field is.  This would be my guess.  Good luck