Your code refers to a form element named aboutusKey on line 19, but no such form element exists.
I think this code:
$UpdateQuery->addFilter("aboutusKey", "=", "i", "".((isset($_POST["aboutusKey"]))?$_POST["aboutusKey"]:"") ."");
Should be:
$UpdateQuery->addFilter("aboutusKey", "=", "i", "".($rsOfficers->getColumnVal("aboutusKey")) ."");