Web Forms :: Reading Values From Dynamic Listbox

I want to display panels based on the check boxes selected on the dynamic checkbox list control. I have been able to dynamically build the check box but have no idea on how to access its checked propety. This is what I am doing but getting error on Request.Form On page load wrote this code.

protected void Page_Load(object sender, EventArgs e)
{
int i;
int chkboxCount = Request.Form("chklist1").Count;
for ( i = 1; i < chkboxCount)
{
String valueChkbox = Request.Form["chklist1"];
}
}