function rand(num) {
			var maxNum = 0;
			j = Math.random();
			for(i=0; i < num; i++) {
				d = Math.random();
				if(d > j) {
					maxNum = i;
					j = d;
				}
			}
			return maxNum + 1;
		}
		
		function natiahniTemy() {
			document.tema1.src = "images/t/" + rand(65) + ".gif";
			document.tema2.src = "images/t/" + rand(65) + ".gif";
			document.tema3.src = "images/t/" + rand(65) + ".gif";
		}