printing delivery slip

The printing delivery slip sequence is defined as follows :

<impression_bl functionloop="0">
 <bl_asperpgi calendar="1">
   <instruction>Sélectionnez un bon de livraison</instruction>
 </bl_asperpgi>
 <bl_asperpgi_report context="bl_asperpgi_report">
   <instruction>Sélectionnez un rapport</instruction>
 </bl_asperpgi_report>
 <report name="bl_asperpgi_report" type="jasper" material="none" save="0" show="1" print="0"/>
</impression_bl>