input type="submit"
is the best way to have a submit button in a form. The downside of this is that you cannot put anything other than text as its value. The button element can contain other HTML elements and content.
Try putting type="submit"
instead of type="button"
in your button
element (source).
Pay particular attention however to the following from that page:
If you use the button element in an HTML form, different browsers will submit different values. Internet Explorer will submit the text between the
<button>
and</button>
tags, while other browsers will submit the content of the value attribute. Use the input element to create buttons in an HTML form.