OnCheckedChanged event of a asp checkbox

<asp:CheckBox ID="CheckBox1"   
    runat="server"   
    AutoPostBack="True"   
    Text="Checkbox control" 
     OnCheckedChanged="CheckBox1_Click"  />  
<br />  
<br />  
<asp:Label ID="Label1"   
    runat="server">  
</asp:Label> 

void CheckBox1_Click(object sender, EventArgs e)  
{  
    throw new Exception("The method or operation is not implemented.");  
}

you can attach the handler dynamically also :-

protected void Page_Load(object sender, EventArgs e)  
{  
    CheckBox1.CheckedChanged += new EventHandler(CheckBox1_Click);  
}

Thanks and Regards
Akiii