                     resolution : @get_resolution()
                     cb         : cb
             else
-                alert_message(type:"error", "Unknown location in '#{file}'.")
+                alert_message
+                    type    : "error"
+                    message : "Unknown location in '#{file}'."
                 cb?()
                 return
         else

                @set_conf(resolution : res)
                @preview.update()
            catch e
                alert_message(type:"error", message:"Invalid resolution #{res}")

    get_resolution: () =>
        if not @preview?

    _show_error_in_file: (mesg, cb) =>
        file = mesg.file
        if not file
            alert_message
                type    : "error"
                message : "No way to open unknown file."
            cb?()
            return
        if not mesg.line
