When returning the results of parse_str() to an array,
the key will be renamed if it contains a period.

$str = "first=value&second[]=this+works&per.iod[]=another";
parse_str($str, $newArray);

echo $newArray;
/* prints "Array" */

echo $newArray['second']['0'];
/* prints "this works" */

echo $newArray['per.iod']['0'];
/* "Undefined index: per.iod " */

/* however...*/
echo $newArray['per_iod']['0']; /* prints "another" */

/* notice the array key has been renamed from per.iod to per_iod */

Glen