public Integer getValueAsNum() throws IllegalArgumentException {
    	if (value == null) {
    		return null;
    	}
    	if (value.length == 1) {			// byte
            return value[0] & 0xFF;
    	} else if (value.length == 2) {		// short
            return ((value[0] & 0xff) << 8 | (value[1] & 0xFF));
    	} else if (value.length == 4) {
            return ((this.value[0] & 0xFF) << 24 |
                    (this.value[1] & 0xFF) << 16 |
                    (this.value[2] & 0xFF) <<  8 |
                    (this.value[3] & 0xFF));
    	} else {
    		return null;
    	}
    }