Dropdown list values get from DB in ASP.net

in .cs file code
------------------
public DataSet LoadValues(string procName, string valueField, string nameField)
{
string retVal = string.Empty;
DataSet ds = new DataSet();
if (procName == "GetList" || procName == "GetStateName")
{
retVal = "--Select--";
}
ds = GetStateValues(procName);
// now construct the option list
if (ds != null)
{
if (ds.Tables[0].Rows.Count > 0)
{
for (int x = 0; x < ds.Tables[0].Rows.Count; x++) { retVal += "" + ds.Tables[0].Rows[x][nameField].ToString() + "";
}
}
}

return ds;
}
===========
code hehind section add the below code:
--------------------------------------
SessionDB sessionDB = new SessionDB();

DataSet ds = sessionDB.LoadValues("GetList", "UserID", "UserName");

if (ds.Tables[0].Rows.Count > 0)
{
dduserid.DataSource = ds.Tables[0];
dduserid.DataTextField = "UserName";
dduserid.DataValueField = "UserName";
dduserid.DataBind();
dduserid.Items.Insert(0, "----Select----");
}

select columns from three different tables using join in sqlserver 2005

--Select values from 3 diff tables
---------------------------------
SELECT DISTINCT A.NAICS,B.NAICSS,C.SIC

FROM #NAICS A JOIN NAIC_SIC..NAICS B ON

A.[NAICS]=SUBSTRING(CAST(B.NAICS AS VARCHAR),1,5)

JOIN [LE-NAICS] C ON

A.[NAICS]=C.NAICS

Hide menus in master page using asp.net

if (Request.QueryString["hid"] != null)
{
if (Request.QueryString["hid"] == "hidelink")
{
_master.ShowHideLinks("hidelinkedarea");
}
}

send this QueryString whenever you need to hide
sample : Response.Redirect("SearchDetails.aspx?cid=" + compid + "&hid=hidelink");

Update(add) values with current values in same column in sqlserver 2005

Create procedure to get XML output in sqlserver 2005

CREATE PROCEDURE [dbo].[GetUsersXML]

AS
BEGIN
SELECT 1 AS TAG,
NULL AS PARENT,
UserID AS [User!1!ID],
UserName AS [User!1!Name]
FROM T_Users
FOR XML EXPLICIT
END