function isValidEmail(email) {
	return /^\w+((-\w+)|(\.\w+))*\@\w+((\.|-)\w+)*\.\w+$/.test(email);
}

function isNumber(event) {
	var keyCode = event.which ? event.which : event.keyCode;
	return keyCode == 13 || keyCode > 47 && keyCode < 58 || keyCode == 8 || keyCode == 9 || keyCode == 46 || keyCode == 35 || keyCode == 36 || keyCode == 37 || keyCode == 39;
}

function FieldOverOut(obj) {
	var val = obj.value;
	if (val == '-- ваш e-mail --') {
		obj.value = '';
	} else if (val == '') {
		obj.value = '-- ваш e-mail --';
	}
}