Browser communication example problem

Hello i am new to Unity.I have unity 5 and builded simple project with it.I wrote a javascript code that has function named MyFunction takes string paramater and attached it to Canvas.This canvas had created when i added Component-->UI-->Text to scene. Canvas has a child component Text that i see on game screen.I can change Text inside of it when debugging.Now i want this text on the scene change according to javascript code example using Html.However there are problems i counter when i try to see some results. This is my NewBehaviourScript.js.I try to understand if MyFunction is ever used if used i will see 1 on screen.

Using javascript example i modified the code below.Example of unity:http://docs.unity3d.com/Manual/UnityWebPlayerandbrowsercommunication.html

 <script type="text/javascript" language="javascript">
 
 //initializing the WebPlayer
 var u = new UnityObject2();
 
 u.initPlugin(jQuery("#unityPlayer")[0], "denemeunity.unity3d");
 
 function SaySomethingToUnity()
 {
  if(u.getUnity()){
 
 alert("hey");
   u.getUnity().SendMessage("Canvas", "MyFunction", "Deneme");
 }   
 }
 SaySomethingToUnity();
 
 </script>

However i believe u.getUnity() doesnt work.Even if i remove if(u.getUnity()) i dont understand why the javascript not working.My object is Canvas and i attached script to it which has MyFunction and if this function worked i should see change in text.But cant see change.

I need help about this problem.I will be really happy with the solution.I dont really like javascript but i need to use it with communication it seems.