// COOKIE FUNCTIONS FROM www.quirksmode.org
function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i=0;i < ca.length;i++) {
		var c = ca[i];
		while (c.charAt(0)==' ') c = c.substring(1,c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
	}
	return null;
}
function eraseCookie(name) {
	createCookie(name,"",-1);
}
// END COOKIE FUNCTIONS

function generateUserName(prefix) {
	var fullDate = new Date;
	var month = fullDate.getMonth() + 1;
	var date = fullDate.getDate();
	var year = fullDate.getYear() % 100;
	var letter = readCookie('seleniumUserLetter');
	if (letter) {
		letter = String.fromCharCode(letter.charCodeAt(0)+1);
	} else {
		letter = 'a';
	}
	createCookie('seleniumUserLetter',letter,1);
	var userName = prefix + (month < 10 ? '0' + month : month) + (date < 10 ? '0' + date : date) + (year < 10 ? '0' + year : year) + letter;
	store(userName,'generatedUserName')
	return userName;
}