[c#]Err: The name X does not exist in the current context

public frmMain()
{...
IniFileReader reader = new IniFileReader(FilePath);
...}

public void Run()
{...
reader.GotoSection("Mail");
...}

The name 'reader' does not exist in the current context

Zakaj?

ali še bolje , podati kot argument(če se izogibamo globalnim varijablam).