JavaScript - Multiple email validation

After a quick research, I wasn't able to find any solution for the multiple email validation using regex (split JS function is not applicable, but some reason back-end of the application waits for a string with emails separated by `;`).

Here are the requirements:

1. Emails should be validated using the following rule: `[A-Za-z0-9\._%-]+@[A-Za-z0-9\.-]+\.[A-Za-z]{2,4}`
2. Regex should accept `;` sign as a separator
3. Emails can be written on multiple lines, finishing with `;`
4. Regex may accept the end of the line as `;`

I come up with this solution:
<pre>
^[A-Za-z0-9\._%-]+@[A-Za-z0-9\.-]+\.[A-Za-z]{2,4}(?:[;][A-Za-z0-9\._%-]+@[A-Za-z0-9\.-]+\.[A-Za-z]{2,4}?)*
</pre>
but it doesn't work for point #3-4

All sort of help will be appreciated

Welcome to DevShed Forums, Johny88.

Why is the "split JS function is not applicable"?