function setCookie (name, value, expires, path, domain, secure){
	var today = new Date();
	today.setTime(today.getTime());
	if (expires){
	  expires = expires * 1000 * 60 * 60 * 24;
	}
	var expires_date = new Date( today.getTime() + (expires));
	document.cookie = name+'='+escape( value ) +
		((expires) ? ';expires='+expires_date.toGMTString() : '' ) + //expires.toGMTString()
		((path) ? ';path=' + path : '' ) +
		((domain) ? ';domain=' + domain : '' ) +
		((secure) ? ';secure' : '' );
}

function getCookie(name){
	var start = document.cookie.indexOf( name + "=" );
	var len = start + name.length + 1;
	if ((!start) && (name != document.cookie.substring( 0, name.length))){
	  return null;
	}
	if (start == -1) return null;
	var end = document.cookie.indexOf(';', len);
	if (end == -1) end = document.cookie.length;
	return unescape(document.cookie.substring(len, end));
}

function deleteCookie (name, path, domain){
	if (getCookie(name)) document.cookie = name + '=' +
		((path) ? ';path=' + path : '') +
		((domain) ? ';domain=' + domain : '' ) +
		';expires=Thu, 01-Jan-1970 00:00:01 GMT';
}

Setting, getting and deleting cookies using Javascript

JavaScript