An object reference is required for the non-static field, method, or property 'System.Web.UI.Page.ClientScript.get'

I am trying to use page client script on database operations in my App_Code/filedb.cs
on DB insert I want to do something like below
using (SqlCommand command = new SqlCommand(sql, con))                 {                     command.ExecuteNonQuery();                     Page.ClientScript.RegisterStartupScript(GetType(), "Success", "alert('Successfully Inserted!');", true);                 }             }         }              &n ...