<? $array = array( ); if (isset($array['foo'])) { print "Foo is {$array['foo']}<br />"; } else { print "Foo is unset<br />"; } parse_str("foo=bar&bar=baz", $array); if (isset($array['foo'])) { print "Foo is {$array['foo']}<br />"; } else { print "Foo is unset<br />"; } ?>