I've often found new programmers have trouble with variable scope. It happens no matter what language you work in and every environment has its own slightly different rules. So, be sure to check out my recent article on Digital Web, aptly titled Variable Scope for New Programmers.
A couple examples:
- C#: variables declared inside an
whilestatement aren't available outside the statement.
- ActionScript: you have timeline and levels scope to worry about.