public static string GetSubDomainID()
{
string domainID = HttpContext.Current.Request.Url.Host;
if (domainID.Contains("/"))
domainID = domainID.Substring(0, domainID.IndexOf("/"));
if (domainID.ToLower().StartsWith("www."))
domainID = domainID.Substring(4);
if (domainID.Contains("."))
domainID = domainID.Substring(0, domainID.LastIndexOf("."));
if (domainID.Contains("."))
domainID = domainID.Substring(0, domainID.LastIndexOf("."));
if (domainID.Contains("."))
domainID = domainID.Substring(0, domainID.IndexOf("."));
return domainID;
}
try this coding to check domain availability ....
Happy coding:)