function isPhoneNumber (checkString)
{   
 if (checkString.charAt(0)=='1') {alert('Do not include the country code prefix!\nThis is canada!');return false;}
	var newString = "";
	for (var i = 0; i < checkString.length; i++) {
        if ((checkString.charAt(i) >= "0" && checkString.charAt(i) <= "9")) {
            newString += checkString.charAt(i);
        }
    }
    return (newString.length == 10) 
}