I want to fetch data from all checked checkboxes inside a repeater into a string on button click

I want to fetch data from all checked checkboxes inside a repeater into a
string on button click

//code is like this
<asp:Button ID="Button1" runat="server" Text="Button"
onclick="Button1_Click" />
<asp:Label ID="Label1" runat="server" Text=""></asp:Label>
<fieldset style="width:310px" >
<legend>paging</legend>
<asp:Repeater ID="rptBooks" runat="server" visible="false">
<HeaderTemplate>
<table style=" border:1px solid #c1650f; width:300px"
cellpadding="0">
<tr style="background-color:#ffa100; color:White">
<td colspan="2">
<b><center>Candidate</center></b>
</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr style="background-color:#ffa100">
<td>
<table style="background-color:#f7f7f7;border-top:1px dotted #c1650f;
width:300px" >
<tr>
<td>
<b>Name:</b>
<asp:Label ID="lblBookName" runat="server" Text='<%#Eval("name") %>'/>
</td>
</tr>
<tr>
<td>
<b>Email:</b>
<asp:Label ID="lblAuthor" runat="server" Text='<%#Eval("email") %>'/>
</td>
</tr>
<tr>
<td>
<b>Qualification:</b>
<asp:Label ID="lblPublisher" runat="server" Text='<%#Eval("qualify") %>'/>
</td>
</tr>
<tr>
<td>
<b>Gender:</b>
<asp:Label ID="lblPrice" runat="server" Text='<%#Eval("gender") %>'/>
</td>
</tr>
<tr>
<td>
<b>Gender:</b>
<asp:CheckBox ID="CheckBox1" runat="server" Text='<%#Eval("gender")
%>' />
</td>
</tr>
</table>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
<div style="overflow: hidden;">
<asp:Repeater ID="rptPaging" runat="server"
onitemcommand="rptPaging_ItemCommand">
<ItemTemplate>
<asp:LinkButton ID="btnPage"
style="padding:8px; margin:2px; background:#ffa100;
border:solid 1px #666; font:8pt tahoma;"
CommandName="Page" CommandArgument="<%# Container.DataItem
%>"
runat="server" ForeColor="White" Font-Bold="True"><%#
Container.DataItem %>
</asp:LinkButton>
</ItemTemplate>
</asp:Repeater>
<asp:Button ID="Button2" runat="server" Text="select"
onclick="Button2_Click" />
</div>
</fieldset>
//C# code..................
public partial class Default5 : System.Web.UI.Page
{
string str;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
// BindRepeater();
}
}
//using my sql database
protected void BindRepeater()
{
MySqlConnection mycon = new
MySqlConnection(@"Server=localhost;Database=reg_info;Uid=root;Pwd=1234;");
mycon.Open();
MySqlDataAdapter msda = new MySqlDataAdapter(str, mycon);
DataSet ds = new DataSet();
DataTable dt = new DataTable();
msda.Fill(dt);
PagedDataSource pgitems = new PagedDataSource();
DataView dv = new DataView(dt);
pgitems.DataSource = dv;
pgitems.AllowPaging = true;
pgitems.PageSize = 2;
pgitems.CurrentPageIndex = PageNumber;
if (pgitems.PageCount > 1)
{
rptPaging.Visible = true;
ArrayList pages = new ArrayList();
for (int i = 0; i < pgitems.PageCount; i++)
pages.Add((i + 1).ToString());
rptPaging.DataSource = pages;
rptPaging.DataBind();
}
else
{
rptPaging.Visible = false;
}
rptBooks.DataSource = pgitems;
rptBooks.DataBind();
}
public int PageNumber
{
get
{
if (ViewState["PageNumber"] != null)
return Convert.ToInt32(ViewState["PageNumber"]);
else
return 0;
}
set
{
ViewState["PageNumber"] = value;
}
}
//for paging protected void rptPaging_ItemCommand(object source,
RepeaterCommandEventArgs e) { PageNumber =
Convert.ToInt32(e.CommandArgument) - 1; str = Session["s1"].ToString();
BindRepeater(); } //I take the string from here used to fetch data
protected void Button1_Click(object sender, EventArgs e) {
str = "select * from reg_info";
Session["s1"] = str;
rptBooks.Visible = true;
BindRepeater();
}
protected void Button2_Click(object sender, EventArgs e)
//here I want the result
{
//Label1.Text = gender;
}