I think there's also an issue of the asynchonous call. see the console output from this:


LABKEY.Query.selectRows({
            schemaName: 'lists',
            queryName: 'Main List',
        success: onSuccess
        });
     
    function onSuccess(data)
    {
        console.log('i will be called second, because the call to the server is asynchronous');
        requirementId = data.rows[data.rowCount-1].Name;
    }
     
    console.log('i will be called first, before the call to the server returns.');
    alert(requirementId);


Bront is also right that you'd have a scope problem too. His suggestion about a new function that is call is probably a good one. however, if onSuccess ends up with only 2 lines (setting the variable and then calling your new function), you might consider just putting your code there.