Hi,

I have 2 custom Date/Time fields for example. 

i) L1 = date/time when case is assigned to Level 1 Support

ii) L2 = date/time when case is assigned to Level 2 Support

I wanted to calculate the time the Case has spent in L1 Support, for example.  I came up with the following logic:

IF(IsNull(L2__c), (ClosedDate - L1__c), (L2__c - L1__c)

Basically, if L2 is null (ie: Case wasn't assigned to L2), then the time spent in L1 is the ClosedDate - L1.   If L2 is not null (ie: Case was assigned to L2), then the time spent in L1 = L2 - L1. 

This is great, but only if the Case is Closed.  

What if the Case is still Open, in L1 Support?

I've tried several IF(AND(IsNull...but I am receiving missing ')' and expecting boolean, etc.  Is there a way to do nested IFs?

Thanks for any tips.

-Mark