In Netlogo, How can I coordinate randomly choosen turtle and it's characteristic?

I just want to build simple market model, and I have a question.

breed [ firms firm ]

breed [ consumers consumer ]

firms-own [ price ]

hogus-own [ money stock ]

globals [ m0 ]

...

and I made 100 customers and 10 firms, and set price of firm randomly from 0 to 10. Also, each consumer has initial capital of 100.

...

to setup

set m0 [ 0 ]

set m0 lput p0 m0

end



to go

tick

buy

sell

set m0 fput p0 m0

end



to-report p0

report [ price ] of one-of firms

end



to-report recent

report item ticks m0

end



to-report past

report item ( ticks - 1 ) m0

end

I made a list so that we can compare current and past price of firm.

But now I faced a problem.

I am trying to find a way to do this.

Each agent will choose random 5 firms out of 10 firms.

And it will compare it's past and current price. If it increased, consumer will buy it( which means increase stock)



to buy

if (recent > past and capital > 0) [

set capital capital - recent0

set stock stock + 1 ]

end



This is the way I tried, but I have a problem. Each agent shoud choose one of random firm. However, Since, every agent is bond by one code, they all buy same firm.

Is there any way to solve this problem?