Hi Shakoor,
The error message is saying that you're not sending an image to Twitpic. You need to POST the image from a form, like this....
<form method='post' action='twitpic' enctype='multipart/form-data'>
<input type='file' name='media' />
Message (optional):<br />
<textarea name='message' style='width:100%; max-width: 400px;' rows='3' id='message'>
</textarea>
<input type='submit' value='Send'>
</form>
HTH
T