Multiple fltr not working.

phpthumbof.php

<php?
//phpthumbof 1.1.0
//Multiple fltr not working. Works only the last filter
//[[*photo:phpthumbof=`&fltr=gray&fltr=flip|y&w=100&h=100&zc=1`]]
//I changed snippet code  from this

 if (!empty($opt[0])) {
 $ptOptions[$opt[0]] = $opt[1];
 }

//to this. Now filters are working.

if (!empty($opt[0])) {     
      if( substr($opt[0],0,4) == 'fltr'){
         $ptOptions['fltr'][] = $opt[1];
       }
      else{
        $ptOptions[$opt[0]] = $opt[1];
       }    
    }