Change month using ajax

Hello!

I have a MyCalendar widget on my wordpress site.
It has a combobox to select the month and a button to switch the calendar to that month, however, when I press the button the entire page refreshes and then the calendar is updated with the new month.

Is there any way to avoid reloading the page and implement or activate ajax? Do I have to do it myself by modifying the code?

Thank you!