I have a form where a button included, when button is clicked the form is submitted, and how to prevent this. for example I just want to show a "alert" when the button is clicked. and put the button outside of form is not a option for me.
and BTW I use bootstrap framework.
    <form class="form-inline" role="form" id="form-area">
        <input type="hidden" name="key" value="dept-area">
        <div class="form-group">
            <input type="text" class="form-control" name="data" placeholder="">
        </div>
        <button class="btn btn-default" id="btn-area">test</button>
    </form>
 
     
     
     
    