If the sum of the hours for a person who has consumed hours on two or more documents in the same week cannot be more than 40 hours, need a alert.

In the example Rafael chage 30 + 16 = 46 This cannot happens 

Need help with the script.

if Staff_ then
    if Hours > 40 then
        alert("Please no More than 40 Hours")
    end
end

The Staff_ is N:1 to Staff table. This work only for only once.