Hai I am doing my final year project in which i design a calculator the calculator will speak the number on which the user places his finger.I have designed the calculator code using jframe and freetts to produce the speech .I have completed the code after executing the jar file i am getting the null pointer execeptioin


java -jar navi.jar

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at spcalc.speak(spcalc.java:46)
at calcula.actionPerformed(calcula.java:108)
at javax.swing.AbstractButton.fireActionPerformed(Abs tractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed (AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed (DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultB uttonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.jav a:6041)
at javax.swing.JComponent.processMouseEvent(JComponen t.java:3265)
at java.awt.Component.processEvent(Component.java:580 6)
at java.awt.Container.processEvent(Container.java:205 8)
at java.awt.Component.dispatchEventImpl(Component.jav a:4413)
at java.awt.Container.dispatchEventImpl(Container.jav a:2116)
at java.awt.Component.dispatchEvent(Component.java:42 43)
at java.awt.LightweightDispatcher.retargetMouseEvent( Container.java:4322)
at java.awt.LightweightDispatcher.processMouseEvent(C ontainer.java:3986)
at java.awt.LightweightDispatcher.dispatchEvent(Conta iner.java:3916)
at java.awt.Container.dispatchEventImpl(Container.jav a:2102)
at java.awt.Window.dispatchEventImpl(Window.java:2440 )
at java.awt.Component.dispatchEvent(Component.java:42 43)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:273)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:173)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:168)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:160)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:121)

any boby can help me pls.