You need to follow the instructions in post 6 of your own thread
here
Note that your image size is fine for the above shot but the file size is tiny (49kb) so its only a quarter of your allowed limit and as such has lost all its detail.
Personally I always reduce the image dimentions first, then sharpen then use the save as command as shown in the thread above, that way I can adjust the apparent sharpness of the shot at it size that it is to be shown on the web and virtually no detail is lost.