Here is my code

        <form class=form-horizontal>



          <div class=control-group>

            <div class=controls>

              <button onclick=javascript:add_user_group(2); class=btn>add</button>

            </div>

          </div>



        <table id=users-table class=table table-striped >

          <thead>

            <tr>

              <th>User Name</th>

              <th>Delete</th>            

            </tr>

          </thead>

          <tbody>



          </tbody>

        </table>



      </form>             

I just want to add a new row to a table when a add button clicked, but it seems a click of the add button triggers a submission of form.

Isn't is only a button with

 type=submit

to submit form. Or any button in a form triggers a submission of form ?