replace blank with lookupvalue

[scabral]

Hi,

i have the following lookupvalue function in SSAS tabular where i am joining on 3 different fields:

=LOOKUPVALUE(StagePolicyCbiPremium[USD Total Amount Effective],StagePolicyCbiPremium[Durable Prospect Client Identifier],'Policy Values'[Durable Prospect Client Identifier],StagePolicyCbiPremium[Durable Policy Identifier],'Policy Values'[Durable Policy Identifier],StagePolicyCbiPremium[Durable Client Business Interest Identifier],'Policy Values'[Durable Client Business Interest Identifier])

sometimes the StagePolicyCbiPremium[USD Total Amount Effective] is blank, but i want to replace it with 0.00 instead.  I tried to use ISBlank function, but keep getting error.  I'm not sure if this is the correct way to do it?

is there a way to replace the value coming backup from the lookupvalue function to a 0 if it is blank?

thanks

Scott