@@ -114,16 +114,6 @@ type ArchiveOptions struct {

 	Path string

 }

-type badParameterError struct {

-	param string

-}

-

-func (e badParameterError) Error() string {

-	return "bad parameter: " + e.param + "cannot be empty"

-}

-

-func (e badParameterError) InvalidParameter() {}

-

 // ArchiveFormValues parses form values and turns them into ArchiveOptions.

 // It fails if the archive name and path are not in the request.

 func ArchiveFormValues(r *http.Request, vars map[string]string) (ArchiveOptions, error) {

@@ -133,11 +123,11 @@ func ArchiveFormValues(r *http.Request, vars map[string]string) (ArchiveOptions,

 	name := vars["name"]

 	if name == "" {

-		return ArchiveOptions{}, badParameterError{"name"}

+		return ArchiveOptions{}, errdefs.InvalidParameter(errors.New("bad parameter: name cannot be empty"))

 	}

 	path := r.Form.Get("path")

 	if path == "" {

-		return ArchiveOptions{}, badParameterError{"path"}

+		return ArchiveOptions{}, errdefs.InvalidParameter(errors.New("bad parameter: path cannot be empty"))

 	}

 	return ArchiveOptions{name, path}, nil

 }