function validatePhoneNumber(id)
{
	var number = document.getElementById(id).value;
	number = number.replace(/^\s+|\s+$/g, '');
	
	if(0 == number.length)
	{
		alert("Type the phone number.");
		return false;
	}
	
	
	var regExp = /^(\d{10})|(((\(\d{3}\)\s*)|(\d{3}-)|(\d{3}\s))\d{3}-\d{4})|(\d{3}\s\d{3}\s\d{4})|(\d{3}\s\d{7})|((\(\d{3}\)\s\d{7}))$/;
	if(!regExp.test(number))
	{
		alert("Invalid phone number format.\r\nSupported formats are: (xxx)xxx-xxxx or xxx-xxx-xxxx.");
		return false;
	}
	return true;
}