Amend Booking Widget JavaScript Code

Hello, I have a small JavaScript code project whereby a hotel website has moved from one CMS to Wordpress and there is a booking widget plugin that has been added to the new WordPress website which needs to have the javascript carried over. I can supply the previous javascript booking widget code and can direct you to the previous website upon project appointment. So in essence once the book now button is pressed the values it passes across to the third party booking engine are: [login to view URL] On the previous website on the button the code was: <img alt="Book Now" id="checkAvailabilityButton" onclick="[login to view URL](['_trackEvent', 'BookingWidget', 'clicked']); [login to view URL](['_setCustomVar', 1, 'Number of Adults', $('#numberOfPersons').val()])" src="/[login to view URL]" title="Book Now" /></td> Let me know if you have any further questions? Regards, Daniel