Fehler: uncaught exception: [Exception... "Illegal operation on WrappedNative prototype object" nsresult: "0x8057000c (NS_ERROR_XPC_BAD_OP_ON_WN_PROTO)" location: "JS frame :: file:///C:/_WebServer/htdocs/jquery-1.4.2.js :: add :: line 5437" data: no]