在整个ASP.net项目中创建/存储的变量如何以及在哪里？

I want to be able to store variables that are accessible to all of the other files in my ASP.net project but can be modified programatically. What I am looking for is something akin to being able to pull information from the web.config file for say the database connection strings (ex System.Configuration.ConfigurationManager.ConnectionStrings["cnDatabase"].ToString())I want to be able to store variables that are a