      <h:form >


                    <script src="https://cdnjs.cloudflare.com/ajax/libs/xlsx/0.18.5/xlsx.full.min.js"></script>


                    <p:commandButton 
                        class="ui-button-success m-1" 
                        icon="fas fa-file-excel" 
                        ajax="false" 
                        value="Download"
                        onclick="exportTableToExcel('tbl', 'grn_return_report')"
                        >
                    </p:commandButton>
            