How to call function in a local script from another local script?

I'm having trouble getting a normal object orientation on the client, so how to do it:

local script1

function eat()
    --body of the function
end

local script2

function sit()
    --body of the function
end

local script3

function doingSomemthing(desition)
    if desition then
        script1.eat()
    else 
        script2.sit()
    end
end

NOTE: this is in the same player

Any help will be appreciated