How do I put a delay in this script ?

I have a fairly simple script that spawns weapons at a choice of locations. Currently it spawns a new weapon the exact moment the old one is collected. How do I go about putting a delay on that?

I thought a simple 'yield WaitForSeconds()' statement would do it, but you having no luck. I've tried adding the waitforseconds before/after almost every line in the script but it either has no effect at all, the weapon spawn goes wild or I get error messages about functions can't be coroutines?

 #pragma strict
 
 var spawnPoint : Transform[]; // Create list of possible spawn locations
 var wepType : GameObject[]; // Creat list of possible weapons to be spawned
 var wepPresent : boolean = false;
 
 function Start()
 {
     SpawnWeapons(); //Run SpawnWeapons coroutine
 }
 
 function Update()
 {    
      if(wepPresent == false) //Check to see if weapon is present
        {
         SpawnWeapons(); //If no weapon is present run SpawnWeapons coroutine
        }
 }
 
 function SpawnWeapons() //Spawns a random weapon at one of possible spawn locations
 {
     var randomLoc : int = Random.Range(0,spawnPoint.length); //Pick random number between the min and max values of the array containing the spawn locations.
     var randomWep : int = Random.Range(0,wepType.length); //Pick random number between the min and max of the array containing the weapon types.
     var newWeapon = Instantiate(wepType[randomWep], spawnPoint[randomLoc].position, spawnPoint[randomLoc].rotation);
     
     newWeapon.GetComponent(DestroySelfOnContact).getSpawnHandler = this.gameObject;
     //Pick random weapon depending on which number was generated by 'randomWep'
     //Spawn weapon at location depending on which number was generated by 'randomLoc'
 
     wepPresent = true;
     
     if(newWeapon.GetComponent(DestroySelfOnContact).destroyed == true)
     {
         wepPresent = false;
     }
 }

Any suggestions please guys ???