[Javascript] Creating waiting points for random movement with NavMesh Script

Hi, Im facing a problem creating waiting points for a NavMesh Script I got on Unity Answers, its pretty much a script just to create random points for the character with NavMeshAgent to move on a NavMesh plane, but problem is that I want the character to pause on every point reached and wait for several seconds before finding a new path and I found out that it is not possible to have a yield on function Update. I tried to add an Idle function after end of path is reached but it doesn't work. I'm new with unity scripting, so I am basically just messing around with the scripts, any ideas on how to make it possible? a solution is much appreciated!

 #pragma strict
 import System.Collections.Generic;
  
 var navMeshScript : navMesh;
 var path : List.<Vector3> = null;
 var targetNodeIndex : int = 0;
 var targetNode : Vector3;
 
 var idleTime = 2;
 
  
 function Start () {
     //Find the navmesh script in the scene
     navMeshScript = GameObject.FindObjectOfType(navMesh).GetComponent("navMesh");
 }
  
 function Idle ()
 {    
 
 //    print ("idle");
     yield WaitForSeconds(idleTime);
     
     while (true)
     {
         yield WaitForSeconds(5);
         
         
     }
 }
     
    
 
 
 function Update () {
 
 
     //If the path is null
     if (path == null) {
         //Find a new random path
         Idle();
         path = navMeshScript.findRandomPath(transform.position);
         targetNodeIndex = 5;
     }
   
     //The end of the path hasn't been reached
     if (targetNodeIndex < path.Count) {
         targetNode = path[targetNodeIndex];
        
         //If the character is close to the target node
         if (Vector3.Distance(transform.position, targetNode) < distanceToNode) {
             //Target the next node
             targetNodeIndex += 1;
         }
     }
     
     //The end of the path has been reached
     else {
         path = null;
         
         
     }
     
 
     transform.position += moveSpeed*(targetNode-transform.position).normalized*Time.deltaTime;
     transform.LookAt(targetNode);
      Idle();
     
     }