public void setStateOneFieldEntered( String digit )
    {
        this.numCount = 1 ;
        notifyObservers() ;
        this.state = field1 ;
        if ( digit != null ){
            if(this.validPin(digit)){

                this.str1 = "(" + digit + ")" ;
                        debug() ;
            }
            else{
                this.invalidPin();
                        debug() ;
            }
        }
        else
            this.str2 = "" ;

    }