Errata

On page 19 it says you can run the code from page 18 and it shows the thumbnail-detail image if you click on for example the guitar. This is not true, cause of the line getDetails(this.title);

This line referce to a function that has not been created yet and has not been mentioned prior in the book. Cause of this function the test on page 19 will fail and leave some people confused on what they did wrong.

A solution would be to either mention to add the line later in the book or mention that for the test this line needs to be commented out.

The code magnet that reads:

if (request == null)

should read:

if (request == null) {

The same error occurs on page 67 with the ordered code magnets.

The callback function is listed as:
"request.onreadystatechange = userNameChecked;"

In the magnets on page 67, 68, and everywhere else from the very next reference on page 73, it is listed as:
"request.onreadystatechange = showUsernameStatus;"

It doesn't look like "userNameChecked" is explained anywhere nearby.

-Nick

Chapter 2

pg 68 if(request == null)
} else {

pg 70 if (request = null)
else {

=============================
pg 68 request.onreadystatechange = showUsernameStatus

pg 70 request.onreadystatechange = userNameChecked

pg 76 showUsernameStatus

Page 81 describes how to modify a status element so that an image changes as a username is validated. The page has us actually make changes to the javascript, but there is no such status element in the HTML file that comes from the headfirst website. So it is impossible to test, and nowhere in the chapter does it have us add such an element. The reason why becomes clear later, eventually we use a completely different method to achieve the goal and do not need a status element. But it is kind of confusing at first, I kept looking to see if I had missed something where I needed to add the element. In the spirit of the books approach, perhaps explain this in the next printing so poor beginners like me do not worry we goofed or missed something. Thanks!

The "correct" fill-in the blank for the next to last line is shown as "getElementById"

I tried this and it did not work. Instead, I had to use

"document.getElementById"

The 'if / else' block in showTab() will append 'Top.png' or
'Down.png' when creating the image sources. This is inconsistent
with the XHTML fragment on page 114, where the image source
suffixes are 'Active.png' and 'Inactive.png'

"a#advanced.inactive means the <a> element with an id of 'tabs' and a class name of advanced"

should be

"a#advanced.inactive means the <a> element with an id of 'advanced' and a class name of inactive"

The request variabele is scoped locally ('var' keyword). Making use of the initialized request object doesn't work in showSchedule() function.

The sentence "So we need to name the fragments beginner.html, intermediate.html and advanced.html" should say "beginners.html" if it is to match the fragment supplied in the Zip file. This error is repeated in the "Get it!" box on page 128.

In fact "beginner" would make more sense in that it is an adjective like the others but the supplied fragment is called beginners.

The initPage code shows two values for onmouseover and two values for onmouseout:

1 currentBtn.onmouseover = showHint; <--
2 currentBtn.onmouseout = hideHint; <--
3 currentBtn.onclick = showTab;
4 currentBtn.onmouseover = buttonOver; <--
5 currentBtn.onmouseout = buttonOut; <--

I think what was intended is that lines 1 & 2 be struck out.

Modifications to function buttonOver():


The text says to change

this.className = "active";

to

me.classNameActivated = "active";


It should say to change it to

me.className = "active";

function buttonOver(e) {
var me = getObject(e);
me.classNameActivated = "active";
}

Should be:
function buttonOver(e) {
var me = getActivatedObject(e);
me.className = "active";
}

The following function - "buttonOut(e)" is correct

The box on the bottom left of the page says you can download examples that match the XHTML given on the page, but the examples on the HeadFirst site do not match the code. The code on the page 182 has a "form" element and on 183 that form is closed. The downloadable sample does not have that form element, and the printed page form refers to a "registration.php" which also does not exist in the downloadable example. Perhaps related, I noticed with the downloadable example for Chapter two that it includes a "thanks.html" file but that file is never used.

The 2nd bullet point says the program to check passwords has a URL of "checkPass.php" This file is not included in the example you download from Head First in order to work on the chapter, in order to get it you have to download the finished website which kind of defeats the purpose. It should come with the starter code.

"Why do you use the parentheses" should be "Why don't you use the parentheses".

The for loop should loop over 'itemDetails' variable and not some 'hero' variable!