data table in ASP.NET 2.0(C#)

//Add a GridView control, one lable controls, four textbox controls and button control in the page .

DataTable myDt;
private DataTable CreateDataTable()
{
DataTable myDataTable = new DataTable();

DataColumn myDataColumn;

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "id";
myDataTable.Columns.Add(myDataColumn);

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "username";
myDataTable.Columns.Add(myDataColumn);

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "firstname";
myDataTable.Columns.Add(myDataColumn);

myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "lastname";
myDataTable.Columns.Add(myDataColumn);

return myDataTable;
}
private void AddDataToTable(string id,string username, string firstname, string lastname, DataTable myTable)
{
DataRow row;

row = myTable.NewRow();

row["id"] = id;
row["username"] = username;
row["firstname"] = firstname;
row["lastname"] = lastname;

myTable.Rows.Add(row);
}
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
myDt = new DataTable();
myDt = CreateDataTable();
Session["myDatatable"] = myDt;

this.GridView1.DataSource = ((DataTable)Session["myDatatable"]).DefaultView;
this.GridView1.DataBind();
}
}

protected void btnAdd_Click(object sender, EventArgs e)
{
if (txtUserName.Text.Trim() == "")
{
this.lblTips.Text = "You must fill a username.";
return;
}
else
{
AddDataToTable(this.TextBox1.Text.Trim(),this.txtUserName.Text.Trim(), this.txtFirstName.Text.Trim(), this.txtLastName.Text.Trim(), (DataTable)Session["myDatatable"]);

GridView1.DataSource = ((DataTable)Session["myDatatable"]).DefaultView;
GridView1.DataBind();

this.txtFirstName.Text = "";
this.txtLastName.Text = "";
this.txtUserName.Text = "";
this.TextBox1.Text = "";
this.lblTips.Text = "";
}
}

Grid View with check boxe Insert all the vlue in maping tble

//DataBase

//first table

CREATE TABLE tbluser(
[UId] [int] IDENTITY(1,1) NOT NULL,
[usreId] [varchar](100) CONSTRAINT [pkuser] PRIMARY KEY CLUSTERED ,
[UserName] [varchar](100)
)
//second table

CREATE TABLE tblGroup(
[GroupId] [int] IDENTITY(1,1)CONSTRAINT [pkGroup] PRIMARY KEY CLUSTERED ,
[GroupName] [varchar](100) )

//third table

CREATE TABLE MapUserGroup(
[usreId] [varchar](100) FOREIGN KEY([Groupid]) REFERENCES [dbo].[tblGroup] ([GroupId]),
[Groupid] [int] FOREIGN KEY([usreId]) REFERENCES [dbo].[tbluser] ([usreId]))


//.cs code

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Master"].ConnectionString);
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
var sql = "select GroupId,GroupName from tblGroup";
DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = new SqlCommand(sql, con);
da.Fill(ds);
if (ds.Tables.Count > 0)
{
gUser.DataSource = ds;
gUser.DataBind();
}
unCheckUserGrid();
}

}
private void unCheckUserGrid()
{
for (int groupcount = 0; groupcount < gUser.Rows.Count; groupcount++) { CheckBox chkGroup = (CheckBox)gUser.Rows[groupcount].FindControl("chkUser"); chkGroup.Checked = false; } } protected void gUser_RowDataBound(object sender, GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.Header) { CheckBox chkGHeader = (CheckBox)e.Row.FindControl("chkUHeader"); chkGHeader.Attributes.Add("onclick", "return maintainState('" + chkGHeader.ClientID + "','" + gUser.ClientID + "');"); } if (e.Row.RowIndex >= 0)
{
CheckBox chkGroup = (CheckBox)e.Row.FindControl("chkUser");
chkGroup.Attributes.Add("onclick", "return uncheckHeader('" + gUser.ClientID + "');");
}
}

string sql = string.Empty;
private void saveall()
{

ArrayList arr = new ArrayList();
CheckBox chk;
Label lbl;
int i;
foreach (GridViewRow d in gUser.Rows)
{
chk = (CheckBox)d.FindControl("chkUser");

if (chk.Checked)
{
lbl = (Label)d.FindControl("lblGroupId");
arr.Add(lbl.Text);
}
}


string userId = txtUserName.Text.Trim().Replace("'", "''");
SqlDataAdapter adp = new SqlDataAdapter("Select usreId from tbluser where usreId='" + userId + "'", con);
DataSet ds = new DataSet();
adp.Fill(ds);
SqlCommand cmd ;
if (ds.Tables[0].Rows.Count > 0)
{
string UId = ds.Tables[0].Rows[0]["usreId"].ToString();
if (arr.Count > 0)
{
for (i = 0; i <= arr.Count - 1; i++) { sql += "insert into MapUserGroup(usreId,groupid) values('" + UId + "','" + arr[i] + "')"; } con.Open(); cmd = new SqlCommand(sql, con); cmd.ExecuteNonQuery(); con.Close(); unCheckUserGrid(); } } } protected void BtnSave_Click(object sender, EventArgs e) { con.Open(); SqlCommand cmd = new SqlCommand("insert into tbluser(usreId) values('" + txtUserName.Text.Trim().Replace("'", "''") + "')", con); cmd.ExecuteNonQuery(); con.Close(); //after save in maping value saveall(); } //Design .aspx page table align="center" >
tr>
td>
span>UserName /span>
/td>
td>
asp:TextBox runat="server" ID="txtUserName" > /asp:TextBox>
/td>
/tr>
/table>
table align="center" >
tr>
td>
div style="overflow: auto">
asp:GridView ID="gUser" AutoGenerateColumns="False"
runat="server"
BackColor="White" BorderColor="#999999" BorderStyle="Double"
BorderWidth="1px" CellPadding="0" Width="100%" Font-Overline="False"
Font-Size="Small" HorizontalAlign="Center" onrowdatabound="gUser_RowDataBound" >
FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
RowStyle BackColor="#EEEEEE" ForeColor="Black" />
Columns>
asp:TemplateField>
HeaderTemplate>
asp:CheckBox ID="chkUHeader" runat="server" />
/HeaderTemplate>
ItemTemplate>
asp:CheckBox ID="chkUser" runat="server" />
/ItemTemplate>
ItemStyle Width="10%" />
/asp:TemplateField>
asp:TemplateField HeaderText="Group Id" HeaderStyle-HorizontalAlign="Left">
ItemTemplate>
asp:Label ID="lblGroupId" runat="server" Font-Size="100%" Text='<%# Bind("GroupId") %>' >
/ItemTemplate>

HeaderStyle HorizontalAlign="Left">
/asp:TemplateField>


asp:TemplateField HeaderText="Group Name" HeaderStyle-HorizontalAlign="Left">
ItemTemplate>
asp:Label ID="lblGroupName" Font-Size="100%" runat="server" Text='<%# Bind("GroupName") %>'>
/ItemTemplate>

HeaderStyle HorizontalAlign="Left">
/asp:TemplateField>

/Columns>
SelectedRowStyle BackColor="#008A8C" ForeColor="White" />
HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" BorderStyle="Double" Font-Size="Small"
HorizontalAlign="Left" />
AlternatingRowStyle BackColor="#DCDCDC" />
/asp:GridView>

/div>

/td>
/tr>
tr>
td align="right" >
asp:Button ID="BtnSave" runat="server" onclick="BtnSave_Click" Text="Save" />
/td>
/tr>
/table>

//.Js file

function maintainState(checkall,Grid)
{
var gvTable=document.getElementById(Grid);
var control=document.getElementById(checkall);

for(var i=1;i {
if(control.checked==true)
{
gvTable.rows[i].cells[0].childNodes[0].checked=true;
}
else
{
gvTable.rows[i].cells[0].childNodes[0].checked=false;
}
}
}

function uncheckHeader(control)
{
document.getElementById(control).rows[0].cells[0].childNodes[0].checked=false;

}