New Post: Web application help

I keep getting this error in relation to sender, do you know what it means?

Error 1 A local variable named 'sender' cannot be declared in this scope because it would give a different meaning to 'sender', which is already used in a 'parent or current' scope to denote something else C:\Users\steph_000\Documents\Visual Studio 2013\Projects\AppPrototype\AppPrototype\Home.aspx.cs 30 34 AppPrototype