public String login (LoginForm lb) throws SQLException, ClassNotFoundException
			{
			ConnectionUtility chd = new ConnectionUtility();
			Connection con = null;
			String role = null;
			ResultSet rs = null;
			PreparedStatement ps = null;
			try {				
				con =chd.create();
				String uid = lb.getUserName();
				String pwd = lb.getPassword();
				ps = con.prepareStatement("select role from LoginDetails where username =? and password=? ");
				ps.setString(1,uid);
				ps.setString(2,pwd);
				rs=ps.executeQuery();
				while(rs.next())
				{
					role=rs.getString(1);
		            
				}
	        } catch(Exception e) {
					e.printStackTrace();
				}
				finally {
					 try  {
						con.close();   
					 } catch(Exception e) {
						e.printStackTrace();
					 }
				}
			return role;
		}