Convert a string to an array (needed for PHP4 compatibility)
|The input string.
$split_length = 1
|Maximum length of the chunk.
Return value summary
|the optional split_length parameter is specified, the returned
array will be broken down into chunks with each being split_length
in length, otherwise each chunk will be one character in length.
FALSE is returned if split_length is less than 1. If the
split_length length exceeds the length of string , the entire
string is returned as the first (and only) array element.