var dvCount = 1;

function writeDiv(){
	var e = document.getElementById('longestDiv');

	if(!e){} else {
		e.innerHTML += '<div style="position:absolute; left:' + (dvCount * 90) +  'px; width:72px; height:50px; border:1px dashed red;">' + dvCount++ + '</div>';
	}

	setTimeout('writeDiv()', 1000);
}

writeDiv();