Need Help in HTML & PHP

You may need Java for that. I am not a Java expert by any means, but my understanding is that a lot of online conditional behaviors (and the condition you've got is checked vs. not checked) are controlled or are better controlled using Java.

For this use Jquery option. Because Jquery has many options for calendar and image functions. I hope it will help you.

Learn jQuery - it'll be best for your purpose.

You need to learn Jquery and there are many jquery plugins available and you can easily use them.

So it is, but every day something is changing and direction too.