If you deleted the contacts on the PC you can put them back on there from the phone by plugging in the phone and making sure it doesn't sync when plugged in. once plugged in select the iPhone is iTunes and hit the info tab on top. Scroll down to where it says replace information on computer with iPhone, or something like that. Select contacts and deselect anything else you want to keep on the computer that is already there. Then the phone should put them back on the computer in the address book.