Hi Rafael, You have to use the TRISTATE attribute in DP_LOCON( "Q...", ... ) call A good version is attached to this mail, Regards, (_) ___ Ludovic JACOMME _ _ ( ) ( ) ( ) ( 6 ) Laboratoire LIP6, Equipe ASIM ( ) (_) ( _ ) Couloir 55-65, 2eme etage, ( )___ ( ) Universite P. et M. Curie (P6) (_____) (_) 4 place Jussieu, 75252 Paris Cedex 05 Tel: (33) 01.44.27.54.15 Fax: (33) 01.44.27.72.80 ICQ: 62526530 mailto: Ludovic.Jacomme@asim.lip6.fr http: //asim.lip6.fr/~ludo