// ####### trim and left, right functions ######

function isNumber(o) {
    var result = !isNaN(o - 0);

    if (result == true) { return 1; }
    else { return 0; }
}

function trim(s) {
    var l = 0; var r = s.length - 1;
    while (l < s.length && s[l] == ' ')
    { l++; }
    while (r > l && s[r] == ' ')
    { r -= 1; }
    return s.substring(l, r + 1);
}

function Left(str, n) {
    if (n <= 0)
        return "";
    else if (n > String(str).length)
        return str;
    else
        return String(str).substring(0, n);
}

function Right(str, n) {
    if (n <= 0)
        return "";
    else if (n > String(str).length)
        return str;
    else {
        var iLen = String(str).length;
        return String(str).substring(iLen, iLen - n);
    }
}

// ###### set and check cookies ######

function getCookie(c_name) {
    if (document.cookie.length > 0) {
        c_start = document.cookie.indexOf(c_name + "=");
        if (c_start != -1) {
            c_start = c_start + c_name.length + 1;
            c_end = document.cookie.indexOf(";", c_start);
            if (c_end == -1) c_end = document.cookie.length;
            return unescape(document.cookie.substring(c_start, c_end));
        }
    }
    return "";
}

function setCookie(c_name, value, expiredays) {
    var exdate = new Date();
    exdate.setDate(exdate.getDate() + expiredays);
    document.cookie = c_name + "=" + escape(value) +
((expiredays == null) ? "" : ";expires=" + exdate.toUTCString());
}

function checkCookie() {
    username = getCookie('username');
    if (username != null && username != "") {
        alert('Welcome again ' + username + '!');
    }
    else {
        username = prompt('Please enter your name:', "");
        if (username != null && username != "") {
            setCookie('username', username, 365);
        }
    }
}

// ###### check for valid email addy ######

function isValidEmailAddress(emailAddress) {

    var pattern = new RegExp(/^(("[\w-\s]+")|([\w-]+(?:\.[\w-]+)*)|("[\w-\s]+")([\w-]+(?:\.[\w-]+)*))(@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(@\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/i);

    return pattern.test(emailAddress);

}