var promocottonURL = "imgs/promocotton1.jpg";

if (document.images) {
     var promocotton1 = new Image();
     promocotton1.src = "imgs/promocotton1.jpg";

     var promocotton2 = new Image();
     promocotton2.src = "imgs/promocotton2.jpg";
	 
	 var promocotton3 = new Image();
	 promocotton3.src = "imgs/promocotton3.jpg";
	 
	 var catalog = new Image();
	 catalog.src = "imgs/catalog.jpg";
}

function changePromocotton() {
     if (document.images) {
        if (promocottonURL == "imgs/promocotton1.jpg") promocottonURL = "imgs/promocotton2.jpg";
		else if (promocottonURL == "imgs/promocotton2.jpg") promocottonURL = "imgs/promocotton3.jpg";
		else if (promocottonURL == "imgs/promocotton3.jpg") promocottonURL = "imgs/catalog.jpg";
		else if (promocottonURL == "imgs/catalog.jpg") promocottonURL = "imgs/promocotton1.jpg";
		
         document.myPromocotton.src = promocottonURL;
	}
}


function changePromocottonBack() {
     if (document.images) {
        if (promocottonURL == "imgs/promocotton1.jpg") promocottonURL = "imgs/catalog.jpg";
		else if (promocottonURL == "imgs/promocotton2.jpg") promocottonURL = "imgs/promocotton1.jpg";
		else if (promocottonURL == "imgs/promocotton3.jpg") promocottonURL = "imgs/promocotton2.jpg";
		else if (promocottonURL == "imgs/catalog.jpg") promocottonURL = "imgs/promocotton3.jpg";
		
         document.myPromocotton.src = promocottonURL;
	}
}