robot framework dropdown test

I have to test a webpage where i have a dropdown with company names and when i select a value i.e particular company in that dropdown, it shows all the users belonging to that company. Right now I have written

Company Users
    click link  id=CompanyUsers
    select from list by value   id=Customer_id  1234
    wait until page contains   1234

But this doesnot seem to be right way of testing. I need to check against all the values in drop down and i have around 1000 values in it. Kindly hep me with this. how should i test this?