C#

[WebMethod Description="Returns true if User ID in Database")]
public bool isUserIdValid( int nUserID )
{
   DataSet myData = new DataSet();

   sqlDataAdapter1.SelectCommand.Parameters["@userID"].Value = nUserID;

   // Check to make sure the stored proc returned rows,
   // otherwise accessing the ds could throw an exception.
   //
   if ( sqlDataAdapter1.Fill( myData, "UserID") > 0 )
   {
      // Validate the returned ID. If the value is not 0
      // then the user is valid.
      //
      if ( myData.Tables["UserID"] != 0 )
      {
         return true;
      }
   }
<br><br>
   return false;
}