Submit with a button who launches Bootstrap Modal

I have a form that i submit with a input type button.

<input class="btn btn-info pull-right" type="submit" value="Post"/><br />

Now id, like to change the submit of my form to a button who also loads the data in a Bootstrap Modal.

<button type="button" class="btn btn-danger" data-toggle="modal" data-target=".bs-example-modal-lg">Post</button>

How do i combine those two?