Catch form action in javascript / jquery?

I have a form that the user can submit using either

<input type="submit" name="delete" value="delete" id="deletebutton" class="pure-button">

or

<input type='submit' id="submitbutton" name="btnSubmit" value="save" class="pure-button pure-button-primary">

I have an event listener that on submit loads a certain function I need to process the form:

document.querySelector('#submitform').addEventListener('submit', function(e) {
    e.preventDefault();
    // Some code goes here
}

However, this code only reacts when btnSubmit is clicked. When delete is clicked the form submits as usual.

How do I avoid that and have another function listening to whether delete is clicked?

Thank you!