[Answered]Rigid body Movement C#

Sorry for all this stuff about movement. I am trying to make a rigid body based player movement.I found this script off of the unify wiki. But I am trying to make a sprinting ability to it. I have been goggling and have found no answer that have fixed the problem. Here is the script that I have been working on.

Edited script

     using UnityEngine;
 using System.Collections;
 
 
 //This script has a problem where you get stuck on walls
 
 [RequireComponent (typeof (Rigidbody))]
 [RequireComponent (typeof (CapsuleCollider))]
 
 public class PlayerMovement : MonoBehaviour 
 {
 
     public float PlayerSpeedWalk = 5.5f;
     public float PlayerSpeedSprint = 15.0f;
 
     public float gravity = 10.0f;
     public float jumpHeight = 2.0f;
 
     public float maxVelocityChange = 15.0f;
 
     public bool IsJump = true;
     public bool IsCrouch = false;
     public bool IsSprint = true;
     private bool grounded = false;
 
     public Vector3 targetVelocity = Vector3.zero;
     
     
     
     void Awake () 
     {
         rigidbody.freezeRotation = true;
         rigidbody.useGravity = false;
     }
     
     void FixedUpdate () 
     {
         if (grounded) 
         {
             // Calculate how fast we should be moving
             Vector3 targetVelocity = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
             targetVelocity = transform.TransformDirection(targetVelocity);
             targetVelocity *= PlayerSpeedWalk;
             
             // Apply a force that attempts to reach our target velocity
             Vector3 velocity = rigidbody.velocity;
             Vector3 velocityChange = (targetVelocity - velocity);
             velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
             velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
             velocityChange.y = 0;
             rigidbody.AddForce(velocityChange, ForceMode.VelocityChange);
             
             // Jump Ability
             if (Input.GetButton("Jump") && IsJump) 
             {
                 rigidbody.velocity = new Vector3(velocity.x, CalculateJumpVerticalSpeed(), velocity.z);
             }
 
 
             //Sprint Ability
 
             //Sprint Bool
 
 
             //Sprint Movement
             if(Input.GetKey(KeyCode.LeftShift))
             {
                 // Calculate how fast we should be moving
                 targetVelocity = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
                 targetVelocity = transform.TransformDirection(targetVelocity);
                 targetVelocity *= PlayerSpeedSprint;
 
                 // Apply a force that attempts to reach our target velocity
                 velocity = rigidbody.velocity;
                 velocityChange = (targetVelocity - velocity);
                 velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
                 velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
                 velocityChange.y = 0;
                 rigidbody.AddForce(velocityChange, ForceMode.VelocityChange);
             }
 
             //Crawl Ability
         
 
         }
         
         // We apply gravity manually for more tuning control
         rigidbody.AddForce(new Vector3 (0, -gravity * rigidbody.mass, 0));
         
         grounded = false;
     }
     
     void OnCollisionStay () 
     {
         grounded = true;    
     }
 
     //Calculates the jump height
     float CalculateJumpVerticalSpeed() 
     {
         // From the jump height and gravity we deduce the upwards speed 
         // for the character to reach at the apex.
         return Mathf.Sqrt(2 * jumpHeight * gravity);
     }
 }

This script comes up with an error that says Assets/Scripts/Player Scripts/PlayerMovement.cs(69,41): error CS0136: A local variable named targetVelocity' cannot be declared in this scope because it would give a different meaning to targetVelocity', which is already used in a `parent' scope to denote something else

I have no clue on how to fix this problem. Any help/advice would be helpful

thanks in advanced

Infinite Gamer