Here is one way of handling the issue. By wrapping the Data Filter in a Modal window you can stop the processing until the selections are made.
dt = Current Data Table();
nw = New Window( "zippy",
<<modal,
obj = dt << Data Filter(
Location( {325, 213} ),
Conditional,
Add Filter(
columns( :Propriétés, :Date d'analyse ),
Display(
:Date d'analyse,
Size( 223, 63 ),
List Display
)
)
)
);
If( nw["button"] == 1,
dtNew = dt << subset(
selected columns( 0 ),
selected rows( 1 )
);
dt << clear row states;
);
Jim