rem: var mimeInfo = mimeService.GetFromTypeAndExtension(aMIMEType, null); 
add: var mimeInfo = mimeService.getFromTypeAndExtension(aMIMEType, null); 
context: function GetExtensionBasedOnMimeType(aMIMEType){  try {    var mimeService = null;    mimeService = Components.classes["@mozilla.org/mime;1"].getService();    mimeService = mimeService.QueryInterface(Components.interfaces.nsIMIMEService);    var mimeInfo = mimeService.GetFromTypeAndExtension(aMIMEType, null);    if (!mimeInfo) return "";    var fileExtension = mimeInfo.primaryExtension;    // the MIME service likes to give back ".htm" for text/html files,    // so do a special-case fix here.    if (fileExtension == "htm")      fileExtension = "html";    return fileExtension;  }  catch (e) {}  return "";}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/86a6cb09cef691c80910300febe692da9477aa22/ComposerCommands.js/buggy/editor/ui/composer/content/ComposerCommands.js