C# class problem

today i developed a web application
I want a feature .
on Login Page:-
if anyone click on submit then his username & password is saved in C sharp class for temprary .
so how can i save username & password to c sharp class & how to i retrive it from Class
anyone give me answer how it can be posibble





note:-
I don't know English but i write my problem in english So if anything is wrong then edit it
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