checkDB();

        function checkDB(){
            var db = window.openDatabase("xRate", "1.0", "Database", 1000);
            db.transaction(xrateQueryPound);
        }

        function xrateQueryPound(tx){

            pound = tx.executeSql('SELECT xrate FROM XRATES WHERE currency = "pound"');
            return pound;
        }

        var pound = xrateQueryPound();