How to use an else if or have a default function in this measure

[Anonymous]

Sorry for the vague title but it was difficult to word. 

To start off with, on my report I have a slicer and a card. As shown below:

As you can see the Card is currently blank, which is a problem. This is because I have a measure in the card that only shows up when a Deal is selected on the slicer. 

This is the measure below, that a kind user on here gave me:

DealPO =

VAR _POTotal = [VO PO Total]

VAR _POBilled = [PO Billed]

RETURN

if( isfiltered('Deals (CRM)'[Deal Name]) ,

SUMX (

VALUES ( 'Deals (CRM)'[Deal Name] ),

IF ( ISBLANK ( _POTotal ), _POBilled, _POTotal )

) , blank())

This works perfectly fine for the Deal slicer by the way, the maths isn't an issue. However, when a Deal isn't selected, I want the card to just display [PO Billed]. I've been trying for hours on implementing this but I've had no luck. I've tried ELSE statements and they don't work. How would I be able to accomplish this? 

[amitchandak · Accepted solution]

@Anonymous , Try like

DealPO =

VAR _POTotal = [VO PO Total]

VAR _POBilled = [PO Billed]

RETURN

if( isfiltered('Deals (CRM)'[Deal Name]) ,

SUMX (

VALUES ( 'Deals (CRM)'[Deal Name] ),

IF ( ISBLANK ( _POTotal ), _POBilled, _POTotal )

) , _POBilled )