Hide parameter form when calling a report

SELECT part_number
FROM part
WHERE part_number = :part_num;

I found that it is impossible to hide the parameter form if I use bind variable in report. So I try to use lexical variable:

SELECT part_number
FROM part
&part_num;

According to my reference book, I can call the report in my form by running [Quoted] the run_product built-in. I have passed the string 'WHERE part_number = :part_num' as the value of the lexical variable &part_num to the report. I have already unchecked the parameter form in the preferences of Report Builder. However, the parameter form still appear....

How can I hide the parameter form if I want to pass a parameter to the report? Do you know the solution? Can you give me a hand?

Thank you very much for your help and kind attention.

-- 
[Quoted] e-mail : c8354710_at_comp.polyu.edu.hk
URL : http://www.comp.polyu.edu.hk/~c8354710