i am using a salesforce platofrm.in which i have access to only onclick function of a button .i have to launch a modal like this code

<!-- Button to trigger modal -->

<a href=#myModal role=button class=btn data-toggle=modal>Launch demo modal</a>



<!-- Modal -->

<div id=myModal class=modal hide fade tabindex=-1 role=dialog aria-labelledby=myModalLabel aria-hidden=true>

  <div class=modal-header>

    <button type=button class=close data-dismiss=modal aria-hidden=true>×</button>

    <h3 id=myModalLabel>Modal header</h3>

  </div>

  <div class=modal-body>

    <p>One fine body…</p>

  </div>

  <div class=modal-footer>

    <button class=btn data-dismiss=modal aria-hidden=true>Close</button>

    <button class=btn btn-primary>Save changes</button>

  </div>

</div>

instead of setting these attributes href=#myModal role=button class=btn data-toggle=modal

how to show modal when user click on the link using onclick function of javascript please guideline