Since the elements are created dynamically you need to use event delegation based handlers
$(function addtop10fromuserpage() {
$(document).on('click', ".addshowtotop10", function () {
var button = $(this);
button.replaceWith('<form><input class="addtop10userinput" type="text" name="seriesname" /><input type="submit" class="button small addtop10usersubmit" value="Add" /></form>');
});
});
$(function addtop10fromuserpageshowadd() {
$(document).on('click', ".addtop10usersubmit", function () {
var button = $(this);
var position = button.closest(".top-rating").find(".top-rating-text").html();
alert('position');
});
});