running=null;  // preferable to declare the interval ID with a null value before you use it
	faces = new Array();
	for (var i=0;i<5;i++){ 
		faces[i] = new Image(); // make each element of the array an Image object
		faces[i].src = "images/glasgow/glasgow"+i+".jpg";// preload .gifs 0-10 into faces[0] to faces[10]
	}
	i=0; 	// will start with image zero, IMG tag loads up the last (eighth) image 
	function animate() {
		document.logo.src=faces[i].src; // replace image
		i++; // increment to next image
		if(i>=5) i=0;  // make sure i does not exceed 10, alternative code: i=i%11;

	}