Submitting the form actually reloads the page, which is what's causing this illusion of jumping to the top of the page. There are 2 things you can do to counteract this.
1) Similar to what Weedpacket suggested, place an anchor tag with a specific name on your page where you want the page "to be" after you submit the form. In the form's action attribute, append #whatever_the_anchor_tag_is.
For example, if the anchor was <a name="notes"></a> then you'd want to append #notes.