var elements = 4;	 //количество div-элементов с текстом
	var time = 10; 		//задержка смены текста по времени в секундах
	var currentText = 0;
	var color = 255;
	noElement = elements + 1;
	time = time*1000;
	function blockRotator () {
		currentText++;
		if (currentText == noElement) {
			currentText = 1;
		}
		if (currentText == 1) {
			prevText = elements;
		}
		else {
			prevText = currentText - 1;
		}
		var hide = document.getElementById('block'+prevText);
		hide.style.display = 'none';
		var show = document.getElementById('block'+currentText);
		show.style.display = 'block';
		setTimeout('blockRotator()', time);
	}
	window.onload = blockRotator;