randomImage(['tb_01_small.jpg','tb_02_small.jpg','tb_03_small.jpg','tb_04_small.jpg','tb_05_small.jpg']);
	function randomImage(imgArr)
	{
		var imgSrc, imgW, imgH, r;
    		r = randomNumber(imgArr.length);
      		imgSrc = imgArr[r];
  		document.write('<IMG SRC=images/'+imgSrc+'>');
  	}