How do I mix these together?

Hi, Im tring to mix this behavior with another... Im tring to get it to not fire more than once on its click. Like my sniper rifle has a speed of 1 shot for every 3 seconds but how it is now you can fire as many times as you press the mouse. (in short Im trying to put a fire rate that works on it)

I tried this.

function MouseClickSoundBehavior::onMouseDown(%this, %modifier, %worldPos)
{ 
        %this.fire(1);
//if ($currentMenu != %this.menuID) return;
  if ( isobject(%this.sound) )       
      %explosion = %this.particleEffect.cloneWithBehaviors();
      %explosion.position = %position;
      %explosion.setEffectLifeMode("Kill", 1.0);
      %explosion.playEffect();
   }
}


}

function MouseClickSoundBehavior::onMouseUp(%this, %modifier, %worldPos)
{
        %this.fire(0);
}


function MouseClickSoundBehavior::fire(%this, %val)
{
   %this.tryingToFire = %val;
   if (%val == 0) 
   {
      cancel(%this.fireSchedule);
      if( !isEventPending(%this.waitSchedule))
         %this.waitSchedule = %this.schedule( %this.fireRate * 1000, "fireCond");
      return;
   }
   
   if (isEventPending(%this.fireSchedule) || isEventPending( %this.waitSchedule))
      return;
   
   if (!isObject(%this.projectile) || !%this.owner.enabled || !%this.owner.getVisible())
      return;
   
   %projectile = %this.projectile.cloneWithBehaviors();
   
   %projectile.setPosition(%this.owner.position);
   %projectile.setRotation(%this.owner.rotation);
   %projectile.setLinearVelocityPolar(%this.owner.rotation, %this.projectileSpeed);
   
   if(%this.fireRate <= 0)	
   {
      cancel(%this.fireSchedule);
      return;
   }

      alxPlay(   %this.sound );

      if (!isEventPending(%this.fireSchedule))
      %this.fireSchedule = %this.schedule(%this.fireRate * 1000, "fire", 1);

This is a behavior I wrote with a little help sorry if it has lots of errors :(