Reading Joystick Values Help

[FearlessLeader]

#include "WPILib.h"
#include <Joystick.h>

class RobotDemo : public SimpleRobot
{
RobotDrive MyRobot;
Joystick RightStick;
Joystick LeftStick;

public:
RobotDemo(void):
MyRobot(1, 2),
RightStick(1),
LeftStick(2)

{
GetWatchdog().SetExpiration(100);
}

void Autonomous(void)
{

}

void OperatorControl(void)
{
GetWatchdog().SetEnabled(true);
while (IsOperatorControl())

{
RightStick.GetX(); //this is what i need help with
}
}
};

START_ROBOT_CLASS(RobotDemo);


I know i use this but RightStick.GetX(); where do i put the float to get the value