Enable to edit 3D Text mesh in Unity3D

Editable3DText.cs

using UnityEngine;
using System.Collections;

namespace Sample
{
	[RequireComponent(typeof(Collider))]
	[RequireComponent(typeof(TextMesh))]
	public class Editable3DText : MonoBehaviour {
		
		TextMesh label;
		TouchScreenKeyboard keyboard;
		
		void Start()
		{
			label = GetComponent<TextMesh>();
		}		
		
		void Update()
		{
			if(isEditing) {
				if(!isMobileRuntime) {
					foreach (char c in Input.inputString) {
						if (c == "\b"[0]) {
							if (keyboard.text.Length != 0) {
								keyboard.text = keyboard.text.Substring(0, keyboard.text.Length - 1);
							}
						}
						else if (c == "\n"[0] || c == "\r"[0]){
							isEditing = false;
							return;
						}
						else {
							keyboard.text += c;
						}
							
					}
				}
				label.text = keyboard.text;
			}
		}
		
		void OnMouseUpAsButton()
		{
			isEditing = !isEditing;
		}
		
		bool isEditing {
			get {
				return keyboard != null;
			}
			set {
				if( value ) {
					keyboard = TouchScreenKeyboard.Open(label.text);	
				}
				else {
					keyboard.active = false;
					keyboard = null;
				}
			}
		}
		
		bool isMobileRuntime {
			get {
				return (Application.platform == RuntimePlatform.Android) || (Application.platform == RuntimePlatform.IPhonePlayer);
			}
		}
		
	}
}

I found it's not working on PC....