// ----------------------------------------------------------------------
// Javascript form validation routines.
// Author: Stephen Poley
// ----------------------------------------------------------------------

var nbsp = 160;		// non-breaking space char
var node_text = 3;	// DOM text node-type
var emptyString = /^\s*$/ ;
var global_valfield;	// retain valfield for timer thread

// --------------------------------------------
//                  trim
// Trim leading/trailing whitespace off string
// --------------------------------------------

function trim(str)
{
    return str.replace(/^\s+|\s+$/g, '');
}


// --------------------------------------------
//                  setfocus
// Delayed focus setting to get around IE bug
// --------------------------------------------

function setFocusDelayed()
{
    global_valfield.focus();
}

function setfocus(valfield)
{
    // save valfield in global variable so value retained when routine exits
    global_valfield = valfield;
    setTimeout('setFocusDelayed()', 100);
}


// --------------------------------------------
//                  msg
// Display warn/error message in HTML element.
// commonCheck routine must have previously been called
// --------------------------------------------

function msg(fld, // id of element to display message in
             msgtype, // class to give element ("warn" or "error")
             message) // string to display
{
    // setting an empty string can give problems if later set to a
    // non-empty string, so ensure a space present. (For Mozilla and Opera one could
    // simply use a space, but IE demands something more, like a non-breaking space.)
    var dispmessage;
    var elem = document.getElementById(fld);
    if (emptyString.test(message)){
        dispmessage = String.fromCharCode(nbsp);
        elem.className='msg';
    }
    else
        dispmessage = message;

    elem.firstChild.nodeValue = dispmessage;

    elem.className = msgtype;   // set the CSS class to adjust appearance of message
    if(message == '') elem.style.display = 'none'; else elem.style.display = 'block' 
}

// --------------------------------------------
//            commonCheck
// Common code for all validation routines to:
// (a) check for older / less-equipped browsers
// (b) check if empty fields are required
// Returns true (validation passed), 
//         false (validation failed) or 
//         proceed (don't know yet)
// --------------------------------------------

var proceed = 2;

function commonCheck(valfield, // element to be validated
                     infofield, // id of element to receive info/error msg
                     required)   // true if required
{   
    if (!document.getElementById)
        return true;  // not available on this browser - leave validation to the server
    var elem = document.getElementById(infofield);
    if (!elem.firstChild) return true;  // not available on this browser
    if (elem.firstChild.nodeType != node_text) return true;  // infofield is wrong type of node

    if (emptyString.test(valfield.value)) {
        if (required) {
            msg(infofield, "error", "This field is required");
            setfocus(valfield);
            return false;
        }
        else {
            msg(infofield, "warn", "");   // OK
            return true;
        }
    }
    return proceed;
}

// --------------------------------------------
//            validatePresent
// Validate if something has been entered
// Returns true if so 
// --------------------------------------------

function validatePresent(valfield, // element to be validated
                         infofield) // id of element to receive info/error msg
{
    var stat = commonCheck(valfield, infofield, true);
    if (stat != proceed) return stat;

    msg(infofield, "warn", "");
    return true;
}

// --------------------------------------------
//               validateEmail
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
// --------------------------------------------

function validateEmail(valfield, // element to be validated
                       infofield, // id of element to receive info/error msg
                       required)   // true if required
{
    var stat = commonCheck(valfield, infofield, required);
    if (stat != proceed) return stat;

    var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
    var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/  ;
    if (!email.test(tfld)) {
        msg(infofield, "error", "Invalid email address");
        setfocus(valfield);
        return false;
    }

    var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/  ;
    if (!email2.test(tfld))
        msg(infofield, "warn", "Probably incorrect email address");
    else
        msg(infofield, "warn", "");
    return true;
}


// --------------------------------------------
//            validatePhoneN
// Validate phone number
// Returns true if so (and also if could not be executed because of old browser)
// Permits spaces, hyphens, brackets and leading +
// --------------------------------------------

function validatePhoneN(valfield, // element to be validated
                       infofield, // id of element to receive info/error msg
                       required)   // true if required
{
    var stat = commonCheck(valfield, infofield, required);
    if (stat != proceed) return stat;

    var tfld = trim(valfield.value);  // value of field with whitespace trimmed off
    var telnr = /^\+?[0-9 ()-]+[0-9]$/  ;
    if (!telnr.test(tfld)) {
        msg(infofield, "error", "Invalid phone number. Use only digits, spaces, brackets and the leading plus character");
        setfocus(valfield);
        return false;
    }

    var numdigits = 0;
    for (var j = 0; j < tfld.length; j++)
        if (tfld.charAt(j) >= '0' && tfld.charAt(j) <= '9') numdigits++;

    if (numdigits < 6) {
//        msg(infofield, "error", "ERROR: " + numdigits + " digits - too short phone number");
        msg(infofield, "error", "Invalid phone number.");
        setfocus(valfield);
        return false;
    }

    if (numdigits > 14)
        msg(infofield, "warn", numdigits + " digit phone number. Make sure that it is correct.");
    else {
        if (numdigits < 10)
            msg(infofield, "warn", numdigits + " digit phone number. Make sure that it is correct.");
        else
            msg(infofield, "warn", "");
    }
    return true;
}

// --------------------------------------------
//             validate Number
// Validate person's age
// Returns true if OK 
// --------------------------------------------

function validateDigit(valfield, // element to be validated
                     infofield, // id of element to receive info/error msg
                     required)   // true if required
{
    var stat = commonCheck(valfield, infofield, required);
    if (stat != proceed) return stat;

    var tfld = trim(valfield.value);
    var num = /[0-9]+?$/
    if (!num.test(tfld)) {
        msg(infofield, "error", "Invalid format");
        setfocus(valfield);
        return false;
    }
    else
        msg(infofield, "warn", "");

    return true;
}

//
function CheckForm(form) {
    var wSpace = /^([a-z][A-Z][0-9])[ \t]+/;
    for (var i = 0; i < form.length; i++) {
        if ((form.elements[i].value == '' || wSpace.test(form.elements[i].value)) && form.elements[i].title.indexOf('is required') > 0) {
            tmp = form.elements[i].title.substr(0, form.elements[i].title.indexOf('is required'));
            alert('Field "' + tmp + '" is required'); setfocus(form.elements[i]); return;
        }

    }
    form.submit();
}