I see there are some errors in your code, such as a missing open curly bracket for your if statement and few others.
Try this:
(function ($) {
$(document).ready(function() {
$("#page").on("swipe",function(){
if($(window).width()<=900) {
$("#nice-menu-1").children("li").children("ul").css({"display": "block", "visibility": "visible"});
}
});
});
})(jQuery);