Java Database Connectivity (JDBC)

hi i am a total newbee to databases in java and only 2 mdr in java

i hava tryed to make a small program
import java.sql.*;
import java.util.*;

public class DataBaseForbindelse {
private Statement stmt;
private Connection forb;
public DataBaseForbindelse() throws Exception {
Class.forName("interbase.interclient.Driver");
forb = DriverManager.getConnection("jdbc:interbase://127.0.0.1/c:/temp/mrmt.gdb","SYSDBA", "masterkey");
stmt = forb.createStatement();
}
public void inds�t(String navn, String ini, String stilling, String pass) throws SQLException {
stmt.executeUpdate("inds�t into ANSAT values('"+navn+"', '"+ini+"', '"+stilling+"', '"+pass+"')");
}
public static void main(String[] args){
System.out.println ("dette er en test");
try {
DataBaseForbindelse dbf =new DataBaseForbindelse();
}
catch (Exception e)
{System.out.println (e.toString());
}
}
}

and i always get this error ?? can anny body help mee ??

java.lang.VerifyError: (class: interbase/interclient/ErrorKey, method: _$372 signature: (Ljava/lang/String;Ljava/lang/String;I)V) Expecting to find unitialized object on stack
at interbase.interclient.JDBCNet._$125484(JDBCNet.java:178)
at interbase.interclient.JDBCNet._$125461(JDBCNet.java:132)
at interbase.interclient.JDBCNet.<init>(JDBCNet.java:75)
at interbase.interclient.Connection._$45044(Connection.java:317)
at interbase.interclient.Connection.<init>(Connection.java:285)
at interbase.interclient.Driver.connect(Driver.java:204)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at DataBaseForbindelse.<init>(DataBaseForbindelse.java:9)
at DataBaseForbindelse.main(DataBaseForbindelse.java:19)
Exception in thread "main"
Process completed.