Java Programming

I have 2 classes:

class1.java uses helper/TradeHelper.java 's connect method.
helper is the package.
class1.java uses this method in its main method.

helper/TradeHelper.java 's connect method, which is static.

Public static Connection connect(String db){
	 Connection conn = null;
	 Properties props =loadProperties();
	 String user = props.getProperty("user");
	 String password = props.getProperty("password");
	 String url = props.getProperty(db);
	 String driver = props.getProperty("driver");
	 
	 try{
		 Class.forName(driver);
		 conn = DriverManager.getConnection(url, user, password);
	 }catch(Exception e){
		 e.printStackTrace();
	 }
	 return conn;
}

Notice in the above code, TradeHelper.java is using other static methods (loadProperties to load a props file) inside of itself.
Not sure why but I keep getting:

java.lang.NoClassDefFoundError: helper/TradeHelper

Ive tried jdk 1.6.0_18 and 1.6.0_20 with no success.
Any ideas?