i use the (ret.sync = stpapi.synchronize.dialog("whinh2120m000", "add", error.sync)) to start the outbound order lines .

but the return value ret.sync = 0

See if this thread helps (http://www.baanboard.com/baanboard/showthread.php?t=25556&highlight=whinh2120m000). If not post your code and someone with Baan 5 experience might see the problem.