need help with SqlCacheDependency

[benmartin101]

I have this code:

        protected void Button3_Click(object sender, EventArgs e)
        {
            DataView dv2 = (System.Data.DataView)Cache["SqlSource"];
            if (dv2 == null)
            {
             
                SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["SampleDBConnectionString"].ConnectionString);
                SqlCommand cmd = new SqlCommand("Select id, product, warehouse, quantity from inventory", con);
                SqlCacheDependency sqlDep = new SqlCacheDependency(cmd);

                SqlDataSource1.SelectCommand = "Select id, product, warehouse, quantity from inventory";
                dv2 = (System.Data.DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty);

                Cache.Insert("SqlSource", dv2, sqlDep, System.Web.Caching.Cache.NoAbsoluteExpiration,new TimeSpan(0, 0, 0, 5));
            }
            int x = dv2.Table.Rows.Count;
            Label2.Text = x.ToString();
        }

For some reason, the Cache is not expiring. What is wrong with this code? I am aware that I could do this using the SqlDataSource1.SqlCacheDependency property, but I'd like to know how to do it using the SqlCacheDependency object. Could someone tell me why this code is not working?