function not been detected on unchecking of checkbox

i have a checkbox that when i check it,it redirects to another function as follows

function Allchecks1(event) {
            event.stopPropagation();
            var market = $(event.target).closest('a');
            var destination = market.attr('data-destination');
            if ((destination == 'null' || destination == 'local') && market.attr('dataid')) {
                var id = market.attr('dataid');
                navigateToEvent(id); // passes the id to this function
                return true;   
            }
            else if (!$('cb').is(':checked')) {
                alert("owiedjiej");     //did a test when i uncheck the textbox nothing happends
            }  
        }

function navigateToEvent(id) {
            var url = '/' + 'List/events/';
            if (id)
                url += id;
        }

the above passes the Id to navigateToEvent function so the output for example is as follows,

/List/events/1111

what i am trying to achieve is that when i untick the check box the id should be removed and my expected output should be

/List/events/

How do i achieve this? i added an alert just for testing purposes on the unticking of the checkbox and it doesnt fire any alerts.

html

<li "><a  data-destination="local" dataid="' + this.MarketID + '" data-nodeid = "' + this.NodeId + '" ><span><input type="checkbox" id="cb" onclick=Allchecks1(event);></span></a></li>');