// Format textbox as US phone number.
function phoneFormat(field, e) {

    var str_keycode;
    var str_digits = '0123456789';

    if (e.keyCode == 8) return true;

    str_keycode = (e.keyCode) ? e.keyCode : e.which;
    var str_code = String.fromCharCode(str_keycode);

    // strip current value of invalid characters
    var str_value = field.value;

    var int_i;
    var str_n = '';

    for (int_i = 0; int_i < str_value.length; int_i++) {
        if (str_digits.indexOf(str_value.charAt(int_i)) >= 0)
            str_n = str_n.concat(str_value.charAt(int_i));
    }

    // Format the phone number
    if (str_n.length > 15)
        field.value = str_n.substring(0, 3) + '-' + str_n.substring(3, 6) + '-' + str_n.substring(6, 10) + ' Ext.' + str_n.substring(10, 15);
    else if (str_n.length > 10)
        field.value = str_n.substring(0, 3) + '-' + str_n.substring(3, 6) + '-' + str_n.substring(6, 10) + ' Ext.' + str_n.slice(10);
    else if (str_n.length > 6)
        field.value = str_n.substring(0, 3) + '-' + str_n.substring(3, 6) + '-' + str_n.slice(6);
    else if (str_n.length > 5)
        field.value = str_n.substring(0, 3) + '-' + str_n.substring(3, 6) + '-';
    else if (str_n.length > 3)
        field.value = str_n.substring(0, 3) + '-' + str_n.slice(3);
    else
        field.value = str_n;

    return true;
}


// Format textbox as US phone number.
function CreditCardFormat(field, e) {

    var str_keycode;
    var str_digits = '0123456789';

    if (e.keyCode == 8) return true;

    str_keycode = (e.keyCode) ? e.keyCode : e.which;
    var str_code = String.fromCharCode(str_keycode);

    // strip current value of invalid characters
    var str_value = field.value;

    var int_i;
    var str_n = '';

    for (int_i = 0; int_i < str_value.length; int_i++) {
        if (str_digits.indexOf(str_value.charAt(int_i)) >= 0)
            str_n = str_n.concat(str_value.charAt(int_i));
    }

    // Format the phone number
    if (str_n.length > 16)
        field.value = str_n.substring(0, 4) + '-' + str_n.substring(4, 8) + '-' + str_n.substring(8, 12) + '-' + str_n.substring(12, 16);
    else if (str_n.length > 12)
        field.value = str_n.substring(0, 4) + '-' + str_n.substring(4, 8) + '-' + str_n.substring(8, 12) + '-' + str_n.slice(12);
    else if (str_n.length > 8)
        field.value = str_n.substring(0, 4) + '-' + str_n.substring(4, 8) + '-' + str_n.slice(8);
    else if (str_n.length > 4)
        field.value = str_n.substring(0, 4) + '-' + str_n.slice(4);
    else
        field.value = str_n;

    return true;
}