Counting number of checkboxes on a asp page

yes it will work if it takes under panel
like bellow
aspx
<asp:panel id="Panel1" runat="server" xmlns:asp="#unknown">

<asp:checkbox id="CheckBox1" checked="true" runat="server">
<asp:checkbox id="CheckBox2" runat="server">
<asp:checkbox id="CheckBox3" runat="server">
<asp:checkbox id="CheckBox4" checked="true" runat="server">
<asp:checkbox id="CheckBox5" runat="server">
<asp:checkbox id="CheckBox6" runat="server">
<asp:checkbox id="CheckBox7" runat="server">

aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
int count = 0;
foreach (Control c in Panel1.Controls)
{
if (c is CheckBox)
{
if (((CheckBox)c).Checked)
count = count + 1;
}
}

ClientScript.RegisterClientScriptBlock(GetType(), "sas", "javascript:alert('" + count + "');", true);

i figured out a work around, as it turns out there is an issue with accessing controls directly inside a ajax control toolkit tab container. My workaround was to put a panel inside of the tab container and then count the controls inside the panel.

In c#
int count=0;
foreach (Control c in this.form1.Controls)
{
if (c is CheckBox)
{
if (((CheckBox)c).Checked)
count = count + 1;
}
}
ClientScript.RegisterClientScriptBlock(GetType(), "sas", "javascript:alert('"+count+"');", true);

In Jquery U can do like this

var count = $("input[type=checkbox]:checked").length;
alert(count);

The page class contains a property called Controls. You can iterate through that list, and check the type. If it's a checkbox, cast it as one, access the "Checked" property, and add. Here's some sample code:

int checkedBoxes = 0;
foreach (Control c in Controls)
   if (c is CheckBox)
      if (((CheckBox)c).Checked)
         checkedBoxes++;