หัดใช้ jpGraph ต้องการที่จะเซ็ต ระยะห่างระหว่างตัวกราฟ กับขอบภาพ ต้องทำยังไงครับ

// Callback function for Y-scale to get 1000 separator on labels
function thai_format($aVal) {
    return number_format($aVal);
}


$data1y = array(2000, 10000, 10000, 10000, 25000, 35000, 80000, 15000, 5000, 100000, 55555, 99999);

// Create the graph. These two calls are always required
$graph = new Graph(940, 700, 'auto');
$graph->SetScale("textlin");
$graph->SetMargin(100, 0, 0, 0);

$theme_class = new UniversalTheme;
$graph->SetTheme($theme_class);

$yFull = array(0, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000);
$yHalf = array(5000, 15000, 25000, 35000, 45000, 55000, 65000, 75000, 85000, 95000);
$graph->yaxis->SetTickPositions($yFull, $yHalf);
$graph->SetBox(false);

$graph->ygrid->SetFill(false);
$graph->xaxis->SetTickLabels(array('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sept', 'Oct', 'Nov', 'Dec'));
$graph->yaxis->HideLine(false);
$graph->yaxis->HideTicks(false, false);


// Create the bar plots
$b1plot = new BarPlot($data1y);

$graph->Add($b1plot);

// Setup the values that are displayed on top of each bar
$b1plot->value->Show();
$b1plot->value->SetFormatCallback('thai_format');

$b1plot->SetAbsWidth(70);
$b1plot->SetColor("#000");
$b1plot->SetFillColor("#cc1111");

$graph_title = "Sale Graph Report of ".date("Y");
$graph->title->Set($graph_title);

// Display the graph
$graph->Stroke();

<div class="row" style="margin-top: 20px;">
        <div class="twelve columns">
            <img src="content/report/graph_show.php">
        </div>
</div>