function categoryGraph(transactions) {
    
    trans = new Transpack();
    
    trans.setTransactions(transactions);
    
    var monthNames = trans.getMonthNames();
    
    var byMonth = trans.getTransactionByMonths();    
    
    var date = new Date();
    var graphData = new Array();
    var i = 0;
    $.each(byMonth, function(){
        
        var amount = 0;
        $.each(this, function(){
            amount += parseFloat(this.getAmount());
            date = this.getRealDate();
        });
        var month = new Array();
        
        var firstInMonth = date.moveToFirstDayOfMonth();
        
        month.push(firstInMonth.getTime());
        i++;
        month.push(amount);
        graphData.push(month);
    });
      
    $.plot($("#graph"), [graphData], {bars: { show: true} });
    //xaxis: { ticks: graphData.labels, autoscaleMargin: 0.02 },
}