if (chkM1.isSelected() && chkM2.isSelected()&&
            chkP1.isSelected() && chkP2.isSelected()&&
            chkP3.isSelected() && chkP4.isSelected()&&
            chkP5.isSelected() && chkP6.isSelected()){
            lblGrade.setText("Grade:Merit");}

               else
                   if (chkP1.isSelected() && chkP2.isSelected()&&
            chkP3.isSelected() && chkP4.isSelected()&&
            chkP5.isSelected() && chkP6.isSelected()){
            lblGrade.setText("Grade:Pass");}

                   else
                       lblGrade.setText("Grade:fail");