Save the Pop-Up window data into database using struts 1.1

[Rahul Kushwaha]

i have two jsp pages, first page has link to open a pop up page ie, second page.

and i want to save the pop-up(second) page containing information into database.
but when i submitted the page i got following error message

Error 500:BeanUtils.populate


(the pop window page has multiple check-box i generated it by using <html:multibox> and i want to save checked check-box into database. i identified that the action dispatch method does not calling while i checked any check-box)

so how can i fix the problem..please reply ASAP.