I'm new for android. I try to write HelloAnroid but when I run the program, there are two errors.
1. Unable to open class file C:\Documents and Settings\Administrator\workspace\HelloAndroid\gen\com\example\helloandroid\R.java: No such file or directory
2. Error generating final archive: Debug Certificate expired on 22/11/2497, 2:29 น.
I don't know why it happens. please help me with these errors.