Oracle Forms

Hello All, I am trying to populate a tab page when an item in a htree is selected with the following WHEN-TREE-NODE-SELECTED trigger and get the error FRM-40350: Query caused no records to be retrieved:

declare
rank number := 0;
begin
rank := ftree.get_tree_node_property('block9.tree10', :system.trigger_node, ftree.node_depth);
if rank = 3 then
show_view('canvas12');
go_block ('tests');
set_block_property ('tests', default_where, 'testcode='||to_number(ftree.get_tree_node_property('block9.tree10',
:system.trigger_node, ftree.node_value)));
message(Get_Block_Property ('tests',default_where));
execute_query;
else
message ('Please select an test node');
end if;
end;

Everything works the way it should, the tab page is shown when the node is selected and I put a message to show the default where that is created and the where looks exactly like it should (i.e. testode=1027) just no records returned. Does anyone know what I am doing wrong. Thanks in advance.