The condition for the 2 fields sort criteria the problem is this.
I have the representation of 2 fields ordered by
1. Discount - open for all users
2. weight
I need to sort was originally on 2 field - weight and if one is already busy 1 field - Discount, then sorting is conducted by him and 2 field-weight was not used, how can I achieve this?

I think possible to accomplish this if 1 field - Discount add independent the default value is not sorted, just outputs the data views, but how do I set the value of 3 in the sort of the same type as the group filters arbitrary value -Any-.
When I do the idea to 1 field value - Discount will not be involved and receive the following 2 field - Weight.
But how do I do this? After all, when you create a sort field has 2 radio buttons - ASC and DESC.
The problem has been solved using the Better Exposed Filters module. 


  The Better Exposed Filters module replaces the Views' default single- or multi-select boxes with radio buttons or checkboxes, respectively. Description fields and Select All/None links can be added to exposed filters to make for a better user experience.