how to do a postback on checkBoxes

Hi all,
 
I'm having 1 or 2 problems with a checkbox.

I have a form that can be either submitted or saved. Within this form there's a number of checkboxes.
I've succesfully achieved this on a textbox (postback) but don't know the syntax for checkboxes
My questions are: how would I open the form with these checkbox's previously checked? In addition to how do I insert the value from a dataSource:
<asp:Parameter Name="NameChange" ...