How to Assign a procedure out variable value to a global variable - form personalization

How to Assign a procedure out variable value to a global variable - form personalization

i am using the below code

='declare

xx_output VARCHAR2(1000);

begin

abc.update('''||${item.DLVY.DELIVERY_ID.value}||''',xx_output );

global.messagetext.value:=xx_output;

end'

but it is throwing error ,i had already defined a global variable a before this step.

I need to captutre the procedure out variable and show it in a message

Thanks

Narendra