Bootstrap multi-select select all option value

I am using bootstrap-multiselect plugin. I have the following client side jquery code:

$("#country").multiselect({
                enableFiltering: true,
                includeSelectAllOption: true,
                numberDisplayed: 2,
                maxHeight: 400,
                buttonWidth: '100%',
                selectAllValue: '0'
            });

when I select the select all option and submit the code i get an array of all other options in server side.But i am assigning the value 0 for the select all option which i am not getting in server side.How can i include the value 0 in the value array when i select the select all option.