Hi Rajesh, your problem is that the web server is not serving Default.aspx when you connect to http://www.sankeypark.org/. Instead, it's probably serving a default index.htm or index.html file that was left there by your hosting company.
You should be able to solve this in your hosting control panel. Make sure that Default.aspx is listed as the first default document that will be served by the site (above any .htm or .html files). In addition, you could also use your file manager to delete any index.htm or index.html file that's sitting in your site root directory.