Character motor Script referece problem

Iam using the script below to change speed of my character while running and walking.The script needs my fps character to be assigned to script in order to access its character motor values like maxForwardSpeed...etc.But Iam not able to drag my fps character on the script in inspector view

var PlayerMotor : CharacterMotor; var PlayerState : float; var PlayerAnimSec : GameObject; var WalkingSpeed : float = 6; var SprintingSpeed : float = 8; var PlayerBossController : CharacterController;

function Update () {

 PlayerStateController();
 PlayerAnims();

}

function PlayerStateController() { if ((Input.GetAxis("Vertical") !=0 || Input.GetAxis("Horizontal") !=0)) { if (Input.GetButton("Sprint")) { PlayerState = 2; } else { if (Input.GetButton("Vertical")) { PlayerState = 1; } else { PlayerState = 0; } } } }

function PlayerAnims() { if (PlayerState == 0) { PlayerAnimSec.animation.CrossFade("idleanimationtrial", 0.4); }
else if (PlayerState == 1) { PlayerAnimSec.animation.CrossFade("walkanimationtrial", 0.4); PlayerMotor.movement.maxForwardSpeed = WalkingSpeed; PlayerMotor.movement.maxBackwardsSpeed = WalkingSpeed/2; PlayerMotor.movement.maxSidewaysSpeed = WalkingSpeed; }
else if (PlayerState == 2) { PlayerAnimSec.animation.CrossFade("sprintanimationtrial", 0.4); PlayerMotor.movement.maxForwardSpeed = SprintingSpeed; PlayerMotor.movement.maxBackwardsSpeed = SprintingSpeed/2; PlayerMotor.movement.maxSidewaysSpeed = SprintingSpeed; } }

 plz help...its urgent ....and thanks in advance