Originally Posted by
theoobe
Sounds like you are attempting to access label1 and textbox1 objects from the outside Form1 class or you are attempting to access objects that do not exist from within Form1 class. Either way it is speculation because you haven't provided code illustrating where the compiler is finding the errors.
Edit: It's worth really learning the basics of C# before trying to create socket applications and so on. Learn about classes, objects, relationships, inheritance, public and private, static and non static. The errors you have mentioned here are not things that should have you searching the internet for help. There are other problems I can forecast you having in the future, just by the code in your original post, for example you are using "blocking" operations within the GUI thread which is not good practice at all.