Check box "create a single pdf document with one sheet per page"

I have Draft sight standard and am a newbie. I have a multi-page schematic and a printer configuration for each page. Under the multiple sheets section of printer dialog I can select the sheets I have created but the check box is not selectable. I'm wondering if its not available on the standard version of Draft sight or I'm missing some step.I'm still a bit foggy on "Sheets" so maybe I'm doing something wrong there. I have created a sheet for each page I want printed. My print configs are for each of these sheets that I created, Any help appreciated.