If your image is shown when you are testing on your computer, but is not working on your website after you will publish on your web server, you have to make your
Image
sub-folder accessible to all users (that will access your website).
To do this you have to add the next settings in your web.config file:
<location path="Image">
<system.web>
<authorization>
<allow users="*" />
</authorization>
</system.web>
</location>