new to JS and it's abilities, need some help...

i want to create a preview button for a backend CMS system - previewing before saved to the DB

i currently have two forms, one where the user enters the title and content (amongst other options) and another form which is hidden.

when the user hits the preview button it runs some JS which rips the title and content from the data entry form into the hidden form. the JS then submits the hidden form which posts to a new window and opens an .aspx page which can retrieve the values and access a database to construct the preview page - this creates a preview without having to save the data.

i don't like having a hidden form!!

is there anyway the JS function can open a new window and post the variables so an .aspx can pick them up - i don't think i can use the querystring to send the content as it could potentially be very very very long!

am i stuck with the solution i have, or is there a way to eliminate the hidden form?