https://www.dropbox.com/s/5dcr90jymtq4f0v/1.PNG?dl=0
 

when i click on submit, without giving second text box value(not mandatory parameter)

it will redirecting to below url(screenshot) 

https://www.dropbox.com/s/w58fl7esnwyxuco/3.PNG?dl=0


but by default not mandatory value check box should be checked here. It's not happening here. 

this is my code block.

prepareURL: function (token) {debugger
        jQuery('<input>').attr({
            type: 'hidden',
            id: 'rs:Auth-token',
            class: 'ssrsReport',
            name: 'rs:Auth-token',
            value: token
        }).appendTo('#report_params');
        var finalVal = '';
        var nullableValues='';
        jQuery('#gen_report input.ssrsInput').each(function () {
            finalVal = jQuery(this).val();
           
            if (finalVal === "") {
                alert('empty value'+jQuery(this));
                nullableValues=nullableValues+'&'+jQuery(this).attr('id')+':isNull=True';
            }
            
            if (jQuery(this).attr('data-type') == 2) {
                var pref_date = preferencesDateToDate(jQuery(this).val(), pref_date_format_num, pref_date_sep_num);
                var the_final_date = pref_date.getFullYear() + '-' + (pref_date.getMonth() + 1) + '-' + pref_date.getDate();
                finalVal = the_final_date;
            }
            // BOOLEAN - CHECKBOX //
            if (jQuery(this).attr('data-type') == 7) {
                debugger
                finalVal = jQuery(this).prop("checked");
            }
            if (jQuery(this).attr('data-type') == 8) {
                finalVal = numPref2Float(jQuery(this).val());
            }
            jQuery('<input>').attr({
                type: 'hidden',
                id: jQuery(this).attr('id'),
                name: jQuery(this).attr('id'),
                class: 'ssrsReport',
                value: finalVal,
            }).appendTo('#report_params');
        });
        jQuery('#loader').hide();
        alert(jQuery('#report_params').html());
        console.log(jQuery('#report_params').html());
        jQuery('#gen_report').attr('action', jQuery("#report_url").val()+nullableValues).submit();
        alert(jQuery("#report_url").val());
        console.log(jQuery("#report_url").val());
        jQuery("#report_params").find("input.ssrsReport[type='hidden']").remove();

here bydefault empty parameter value check box should be checked by default when report is loading. But it's not happening.  please help me here to achieve this. 

Thanks

Chandu