I am using this button to insert data into a storage database:

HTML Code:
<div class="bookmark"><input type="button" class="addBM" value="Add Bookmark" onclick="insertRow('100', window.location.pathname, document.title)"></div>
However, although the rows are being inserted, all the data is undefined. Here is the insert statement:

Code:
function insertRow() {
db = window.openDatabase("Database", "1.0", "Bookmarks", 200000);
db.transaction(function(tx) {
	var id;
	var filename = window.location.pathname;
	var title = document.title;
	tx.executeSql("insert into BOOKMARKS(id, filename, title) values(?,?,?)",[id, filename, title]);
	}, errorCB,successCB()); alert('Bookmark added.');
}
What's the proper syntax to carry the data to the DB? There are no errors in the console, and the alert pops up at the right time.