how to avoid default form action on laravel 5.4?

i integrate my html form on laravel. it has html registration form. in that form i didn't put form action . so when i submit the form it post the data to the same page.but i write a javascipt click event to get form data and post data to the destination with ajax. but when i click the submit button i perform these two actions .. 1. posting data to the same page and another my ajax call.. i want only ajax. not that .. how to solve this?

<form class="form-horizontal" role="form" id="addUser">input fields</form>
$('#addUser').on('click',function(){some code})

via Chebli Mohamed