Java Card

Hi,

I am new to javacard. I have writeen an applet, but when i install it using jcwde it give me this error :
Exception from the invoked install() method:public static void test.SecuritySimulator.install(byte[],short,byte)
Exception in thread "main" java.lang.NullPointerException
at com.sun.javacard.impl.PrivAccess.selectOnly(PrivAccess.java:129)
at com.sun.javacard.impl.PrivAccess.selectDefaultApplet(PrivAccess.java:116)
at javacard.framework.Dispatcher.cardReset(Dispatcher.java:173)
at javacard.framework.Dispatcher.main(Dispatcher.java:64)
at javacard.framework.JCWDEDispatcher.main(JCWDEDispatcher.java:28)
at com.sun.javacard.jcwde.Main.run(Main.java:85)
at com.sun.javacard.jcwde.Main.main(Main.java:148)

I just have 2 lines in the install() method :

b = new byte[10];
hash = MessageDigest.getInstance(MessageDigest.ALG_SHA, false);

I did some hit 'n' trial and found out that if i comment the second line, this exception disappears. Am I supposed to do something for using javacard.secuirty package in jcwde ??


Thanks in advance,
Kohinoor