Need help with nesting If formulas

[Cara Hunter]

I have a formula that I am trying to combine another IF statement too, but I keep receiving errors.  Here is my statement that is working without the extra IF:

=IF(AND(I4<>"",D4="Service Completed"),"",TODAY()-I4)

 The problem is that this formula also calculates when I4 is blank and I only want it to calculate Today-cell if there is data in the cell. So I tried to put another IF statement, but it give me an error.  Here is what I tried:

=IF(AND(I4<>"",D4="Service Completed"),"",TODAY()-I4,IF(I4="",""))

[#2]

@Cara Hunter 

Does this perform the calculation you require?

=IF( (Date<>"") * (Status<>"Service Completed"), TODAY()-Date, "" )

Essentially, it calculates days overdue of an open task provided a termination date exists.