Error Code CS0103

This error means that you are trying to use a name that doesn't exist in that scope, presumably because you accidentally defined it in the wrong scope, or because you spelled it incorrectly.

Without your code in front of me, I can't really tell you exactly how to fix it, but look through what you have to make sure that you haven't made any silly mistakes. For example, variableName != varablename - the language is case-sensitive.