Added target _blank to print button

pages/examples/invoice.html

@@ -580,7 +580,7 @@
           <!-- this row will not appear when printing -->
           <div class="row no-print">
             <div class="col-xs-12">
-              <a href="invoice-print.html" class="btn btn-default"><i class="fa fa-print"></i> Print</a>
+              <a href="invoice-print.html" target="_blank" class="btn btn-default"><i class="fa fa-print"></i> Print</a>
               <button class="btn btn-success pull-right"><i class="fa fa-credit-card"></i> Submit Payment</button>
               <button class="btn btn-primary pull-right" style="margin-right: 5px;"><i class="fa fa-download"></i> Generate PDF</button>
             </div>