bootstrap modal crashing when setting value

[Mad_Davil]

In my website I'm trying to use bootstrap modal to ask for two values and get the middle of it. I have a button that when clicked, calculates the middle of the two values and sets a value I have declared in the modal-body code. It sets the value and then the modal disappears and the webpage reloads. Can you tell me what I'm doing wrong?In the HTML, modal-body: \[code\]<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">