Oracle Forms

Dear professionals,

I'm facing the next problem - I have to disable all but one items on the form.

Now, I can set property for the block:

set_block_property ('MYBLOCK', update_allowed, property_false);
set_block_property ('MYBLOCK', insert_allowed, property_false);

But I'm unable to enable item1 for update like this:

set_item_property ('MYBLOCK.item1', enabled,property_true);
set_item_property ('MYBLOCK.item1', update_allowed,property_true);
set_item_property ('MYBLOCK.item1', insert_allowed, property_true);

Application raising this error: FRM-41017: Cannot set UPDATE ALLOWED attribute of non-enabled item

I know that I could enable/disable any item one by one, but I have to much items on the block.

I'm using Forms 11gR2

Thanks in advance