script

    using UnityEngine;
    using System.Collections;

    public class script : MonoBehaviour {

            public float currentSpeed;
            public float walkSpeed            = 6F;
            public float maxSpeed             = 15F;
            public bool swiming               = false;
            public bool climbing              = false;
            public float rotateSpeed          = 100F;
            public bool checker               = false;
            public Vector3 moveDirection      = Vector3.zero;
            public float jumpSpeed            = 8F;
            public float sprintCurHealth      = 0F;
            public int sprintMaxHealth        = 50;
            private int _PercentFull          = 100;
            public bool isSprinting           = false;
            public float gravity              = 20.0F; //set to Public
            //-------------------------------------------//
            private bool grounded             = false; //Had to set it to true for the script to work on its own.
            static public bool allowMove      = true;
            static public bool playerSneaking = false;

            void Awake (){
                    sprintCurHealth = sprintMaxHealth;
            }

            void Update(){
                    if (isSprinting==true){
                            currentSpeed = maxSpeed;
            }
                    else {
                            currentSpeed = walkSpeed;
                    }
                    if (Input.GetKey("left shift") && Input.GetKey("w")){
                            if (sprintCurHealth > 0){
                                    isSprinting = true;
                            }
                            else{ //if sprintCurHealth is not more than 0, it must be equal to or smaller than 0.
                                    isSprinting = false;
                            }
                    }
                    if (sprintCurHealth > sprintMaxHealth){
                            sprintCurHealth = sprintMaxHealth;
                    }
                    if (isSprinting==true){ //it make the script more readable if you're more specific.
                            sprintCurHealth =- Time.deltaTime;
                    }
                    else{ //if it's not true, it must be false. You should use else here.
                            sprintCurHealth =+ Time.deltaTime;
                    }
                    transform.Rotate(0,Input.GetAxis("Mouse X") * rotateSpeed * Time.deltaTime, 0);
            }

            void FixedUpdate() {
                    if (Input.GetKeyDown("q")){
                            moveDirection.y = jumpSpeed;
                            //animation.Play("roll");
                            //Roll();
                    }
                    if(allowMove==true){
                            if (grounded==true) {
                                    moveDirection = new Vector3(Input.GetAxis("Horizontal")*currentSpeed, 0, Input.GetAxis("Vertical")*currentSpeed);
                                    moveDirection = transform.TransformDirection(moveDirection);
                                    moveDirection *= currentSpeed;
                                    if(swiming==false){
                                            if (Input.GetKey(KeyCode.Q)) {
                                                    moveDirection.y = jumpSpeed;
                                                    //Roll();
                                            }
                                            else if (Input.GetKeyDown(KeyCode.Space)) { //you don't have to check for the jump key if you're already pressing Q.
                                                    moveDirection.y = jumpSpeed;
                                            }
                                    }
                            }
                            else if (climbing==true){
                                    moveDirection = new Vector3(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical"),0);
                                    moveDirection = transform.TransformDirection(moveDirection);
                                    moveDirection *= currentSpeed;
                            }
                    }
                    if(swiming==true){
                            currentSpeed = walkSpeed;
                    }
                    transform.position += moveDirection;
            }
    }