Finding cookies in C

if (Request.Cookies["fakecookiename"] != null)
{
Response.Redirect("default.aspx");
}

Where "fakecookiename" is replaced with a unique name for you cookie that you made with the previous code.

and the response.redirect of the action if the value is not null. You can do pretty much anything in the statement, it doesnt just have to be a page redirect.