How to handle check box and print 1 row of item

Hi All

I have a question. Before that let's me explain, I had add in a Print Summary check box in the dialog screen. When user ticked, it will print 1 row of item otherwise it will print all the item as the current report. Now I would like to ask, How to write the code and how to generate the code? where to write that code? I'm a newbie in Dynamic AX. Someone please help me.