Is there something wrong with my c# script?

I Can't seem to figure out what the issue is here. Once i play the game, I go to my trigger collider, the GUI message appears, but when I click 'E', I get a "key not mapped" error. I tried swapping "E" for "KeyCode.E". But then I just don't get anything once I click "E".

 using UnityEngine;
 using System.Collections;
 
 public class Scene_Prctice : MonoBehaviour 
 {
     public bool showGUI = false ;
 
     //transition to next scene/button show/button press
     //
     //
     //
     //
 
     void OnTriggerEnter (Collider other) //char enters collision trigger
     {
     
         if(other.CompareTag("Player")) //if char tag is "player"
     {
             showGUI = true;
     }
         if (Input.GetKeyDown(KeyCode.E)) //= "Press 'E' To Enter";
         {
             Application.LoadLevel("noWhere");
         }
     }
 
     public void OnTriggerExit (Collider other) //char enters collision trigger
     {
     
         if(other.CompareTag("Player")) //if char tag is "player"
     {
         showGUI = false;
     }
     }
             
            //Application.LoadLevel ("noWhere"); //Loads the level
     public void OnGUI()
     {
         if(showGUI)
         {
             GUI.Box (new Rect(400,200,200,20), "Press 'E' To Continue");
     }
     }
     //
     //
     //
     //
     //
     //
 }