Stopping formula from returning DIV/0 or #Num! error 1

[CMooreJr]

Hey all! I have a report with 2 fields,

"UnitsSold" and "PrevTotSold"

I need to calculate the percentage of change in these fields. I have created a textbox with the control source..
=([UnitsSold]-[PrevTotSold])/[PrevTotSold] set as a percent. This works great if there are units sold and previous units, but if [PrevTotSold] happens to be 0, then I get a Div/0 error. This should really be 100 percent. If the [UnitsSold] is zero, I get a #Num! error..this should be 0%. How can I say Div/0=100% and #Num!=0%

or is there a better way to do it??

Thanks for your help!!!!

 

[CajunCenturion]

A nested IIf statement should work, checking for these boundary conditions.
=IIf(([UnitsSold]=0),0,IIf(([PrevTotSold]=0),100,([UnitsSold]-[PrevTotSold])/[PrevTotSold]))

Good Luck
--------------
As a circle of light increases so does the circumference of darkness around it. - Albert Einstein

 

[teddyatjorundotnet]

=([UnitsSold]-[PrevTotSold])/iif([PrevTotSold] = 0 , 1, [PrevTotSold])