UI 4.6 left right button movement problem

HI...Please help me with this.Would be very thankful I have added buttons in my game.(New UI 4.6) I want my character to jump and move left and right. Jump is working fine. But facing problem with movement buttons(left/right).Player is moving little distance with single mouse click. I want it to be like if button is pressed player will continue moving in direction.and when released player will stop. I am using this below script.Please help me.

using UnityEngine; using System.Collections; using UnityEngine.UI;

public class PlayScene : MonoBehaviour { // movement config public float gravity = -25f; public float runSpeed = 8f; public float groundDamping = 20f; // how fast do we change direction? higher means faster public float inAirDamping = 5f; public float jumpHeight = 3f; public static bool flip;

 public Button jump_puppy;
 public Button left_puppy;
 public GameObject dog;


 private bool canDoubleJump = false;

 [HideInInspector]
 private float normalizedHorizontalSpeed = 0;
 
 private CharacterControl _controller;
 private Animator _animator;
 private RaycastHit2D _lastControllerColliderHit;
 private Vector3 _velocity;

 void Awake()
 {
     _animator = GetComponent<Animator>();
     _controller = GetComponent<CharacterControl>();
     
     // listen to some events for illustration purposes
     _controller.onControllerCollidedEvent += onControllerCollider;
     _controller.onTriggerEnterEvent += onTriggerEnterEvent;
     _controller.onTriggerExitEvent += onTriggerExitEvent;
 }

 void Start () 
 {
     dog = GameObject.FindWithTag ("Player");
 }
 
 #region Event Listeners
 
 void onControllerCollider( RaycastHit2D hit )
 {
     // bail out on plain old ground hits cause they arent very interesting
     if( hit.normal.y == 1f )
         return;
     
     // logs any collider hits if uncommented. it gets noisy so it is commented out for the demo
     //Debug.Log( "flags: " + _controller.collisionState + ", hit.normal: " + hit.normal );
 }
 
 
 void onTriggerEnterEvent( Collider2D col )
 {
     Debug.Log( "onTriggerEnterEvent: " + col.gameObject.name );
 }
 
 
 void onTriggerExitEvent( Collider2D col )
 {
     Debug.Log( "onTriggerExitEvent: " + col.gameObject.name );
 }
 
 #endregion
 
 
 // the Update loop contains a very simple example of moving the character around and controlling the animation

 public void jumpa()
 {
     _velocity = _controller.velocity;
     
     if( _controller.isGrounded )
         _velocity.y = 0;
     if(_controller.isGrounded)
     {
         canDoubleJump = false;
         _velocity.y = Mathf.Sqrt( 2f * jumpHeight * -gravity );
         _animator.Play( Animator.StringToHash( "Jump" ) );
     }
     
     else {
         if(!canDoubleJump)
         {
             canDoubleJump = true;
             _velocity.y = Mathf.Sqrt( 2f * jumpHeight * -gravity );
         }
     }
     // apply horizontal speed smoothing it
     var smoothedMovementFactor = _controller.isGrounded ? groundDamping : inAirDamping; // how fast do we change direction?
     _velocity.x = Mathf.Lerp( _velocity.x, normalizedHorizontalSpeed * runSpeed, Time.deltaTime * smoothedMovementFactor );
     
     // apply gravity before moving
     _velocity.y += gravity * Time.deltaTime;
     
     _controller.move( _velocity * Time.deltaTime );
 }

 public void lefta(){
     // grab our current _velocity to use as a base for all calculations
     _velocity = _controller.velocity;
     
     if( _controller.isGrounded )
         _velocity.y = 0;
     flip = false;
     normalizedHorizontalSpeed = -1;
     if( transform.localScale.x > 0f )
         transform.localScale = new Vector3( -transform.localScale.x, transform.localScale.y, transform.localScale.z );
     
     if( _controller.isGrounded )
         _animator.Play( Animator.StringToHash( "Run" ) );


     // apply horizontal speed smoothing it
     var smoothedMovementFactor = _controller.isGrounded ? groundDamping : inAirDamping; // how fast do we change direction?
     _velocity.x = Mathf.Lerp( _velocity.x, normalizedHorizontalSpeed * runSpeed, Time.deltaTime * smoothedMovementFactor );
     
     // apply gravity before moving
     _velocity.y += gravity * Time.deltaTime;
     
     _controller.move( _velocity * Time.deltaTime );
 }

 void Update()
 {
     // grab our current _velocity to use as a base for all calculations
     _velocity = _controller.velocity;

     if( _controller.isGrounded )
         _velocity.y = 0;


     if( Input.GetKey( KeyCode.RightArrow ) )
     {
         flip = true;
         normalizedHorizontalSpeed = 1;
         if( transform.localScale.x < 0f )
             transform.localScale = new Vector3( -transform.localScale.x, transform.localScale.y, transform.localScale.z );
         
         if( _controller.isGrounded )
             _animator.Play( Animator.StringToHash( "Run" ) );
     }
     else if( Input.GetKey( KeyCode.LeftArrow ) )
     {
         flip = false;
         normalizedHorizontalSpeed = -1;
         if( transform.localScale.x > 0f )
             transform.localScale = new Vector3( -transform.localScale.x, transform.localScale.y, transform.localScale.z );
         
         if( _controller.isGrounded )
         _animator.Play( Animator.StringToHash( "Run" ) );
     }
     else
     {
         normalizedHorizontalSpeed = 0;
         
         if( _controller.isGrounded )
             _animator.Play( Animator.StringToHash( "Idle" ) );
     }
     
     
     // we can only jump whilst grounded
     if(_controller.isGrounded && Input.GetKeyDown( KeyCode.UpArrow ) )
     {
         canDoubleJump = false;
         _velocity.y = Mathf.Sqrt( 2f * jumpHeight * -gravity );
         _animator.Play( Animator.StringToHash( "Jump" ) );
     }

     else {
         if(!canDoubleJump && Input.GetKeyDown( KeyCode.UpArrow )){
             canDoubleJump = true;
             _velocity.y = Mathf.Sqrt( 2f * jumpHeight * -gravity );
     }
     }
     
     // apply horizontal speed smoothing it
     var smoothedMovementFactor = _controller.isGrounded ? groundDamping : inAirDamping; // how fast do we change direction?
     _velocity.x = Mathf.Lerp( _velocity.x, normalizedHorizontalSpeed * runSpeed, Time.deltaTime * smoothedMovementFactor );
     
     // apply gravity before moving
     _velocity.y += gravity * Time.deltaTime;
     
     _controller.move( _velocity * Time.deltaTime );
 }
 

}