books list library js

gistfile1.js

$(document).ready(function(e) {
  //localStorage.clear();
	var c = $("#content");
	var txtNr = $("#txtNr");
	var butNr = $("#butNr");
	var count = 0;

	var booksBought = [];
	var books = [309,
				365,
				428,
				481,
				482,
				483,
				484,
				488,
				489,
				490,
				491,
				492,
				720,
				835,
				837,
				838,
				844,
				845,
				891,
				904,
				905,
				930,
				973,
				974,
				976,
				989,
				1012,
				1071,
				1104,
				1128,
				1129,
				1152,
				1194,
				1120,
				1145,
				1305,
				1347,
				1351

				// write here new book number 
				];
						
	butNr.click(
		function () {
			
			if ((txtNr.val() == "") || (isNaN(txtNr.val()))) {
				txtNr.val("Not valid!");
			} else {
				booksBought.push($('#txtNr').val());
				localStorage['booksBought'] += booksBought;
				
				for (var i = 0; i < localStorage.length; i++){
				    alert(localStorage.getItem(localStorage.key(i)));
				}

			}
		});

    for (var i = 1; i <= 1500; i++) {
		if (books.indexOf(i) >= 0) {
        	c.append("<span style='color:red;'>" + i + "</span><br />");
			count++;
   		}
    	else {
        	c.append(i + "<br />");
    	}
	}
	document.title = "biblioteca pentru toti: " + count + "/1500 carti";
});