If you want the buttons inside the form, have you tried changing them to inputs instead: <input id="editbutton" type="button" value="Edit">, or at least adding the type="button" attribute to the existing <button> tags?
Depending on the browser, the <button> element may default to type="submit" (which submits the form) rather than type="button" (which doesn't do anything unless you intercept the click event in JavaScript).
-Carl V.