jSignature_Tools_Base30.php uncompress_stroke_leg() index error

[mc2]

Hi, I got this: Error type: 8, in file: C:\ ... \jSignature_Tools_Base30.php, line: 107, message: Undefined index: :

I created this kludge, but I don't know the code/image format and won't presume to create a pull request. FYI.

105            } else /* alphas replacing digits */ {
106                // more parts for the new number
+++               if (array_key_exists($ch, $charmap_reverse)) {
107                  array_push( $partial, $charmap_reverse[$ch]);  
+++                }                                               
            }