function (pageNum) {
            var imgPath = util.template(config.template.img, { page: pageNum });
            return config.url + imgPath + config.queryString;
        }
function (pageNum) {
            var imgPath = util.template(config.template.img, { page: pageNum });
            return config.url + imgPath + config.queryString;
        }
function ( pageNum ) { var imgPath = util . template ( config . template . img , { page : pageNum } ) ; return config . url + imgPath + config . queryString ; }
Build and return the URL to the PNG asset for the specified page
@param   {number} pageNum The page number
@returns {string}         The URL
Build and return the URL to the PNG asset for the specified page