Help Needed with "If" Formula

Help Needed with "If" Formula

I need the total number of Ads for Conferences, which would be distributed in "Welcome Packets"

I have attendance by professions.  My formula works by just adding the professions.  But I need to implant an "if" formula.  My Outreach methods include:  Trainings, Booths/Displays, Ads.  I need the summing of the attendance "if" Methods_Field == Ads.

I've tried MANY formats, the "sumif" function worked in Excel that the db was imported from.  

Here is what I have now:

If(input.Method_Field==input.Ad)

(RCC_Staff  +  Law_Enforcement  +  Legal_System_Prof  +  Healthcare_Prof  +  Social_Services  +  Educational_Prof  +  DV_Prof  +  Disabilities_Specialists  +  College_University  +  Multidisciplinary)