get value from unselected checkbox

i got a problem with checkbox in html usage.

I have some checkboxes with some names which are already loaded.In which some are checked(tick) by default, now i want to do unselect the checkbox which are checked by default and select the other checkbox which was unselect, Here how can i find out which was unselected in list of checkboxes. i read about hidden field but not getting much idea.

Eg: having 10 checkboxes with diff. name and 4 are checked by default and i was unselecting the checkbox and selecting the other two how to get unselected checkbox name and value. i m doing with c++ with html no jquery

Thanks in advance and help me to get out from this.