[ruslan_mart]

<div id="modalWin" style="background: #202020; border: 1px solid #888; color: #AAA; display: none; height: 60px; left: 50%; margin-left: -100px; padding-top: 60px; position: fixed; text-align: center; top: 150px; width: 200px">Модальное окно</div>

function cookie(a, b) {
	if(b) document.cookie = a+'='+escape(b)+'; expires = Mon, 01-Jan-2999 00:00:00 GMT; path=/';
	var c = '(?:; )?'+a+'=([^;]*);?', d = new RegExp(c);
	return d.test(document.cookie) ? decodeURIComponent(RegExp['$1']) : 0;
}

window.onload = function() {
	if(!cookie('view')) {
		document.getElementById('modalWin').style.display = 'block';
		cookie('view', true);
	}
}