CS81 – Pete Thottam

Unit
9 – chapter 6: 10, 14

#10. Implement a web page that presents an “account
sign-up” form, with text input fields for a user’s real name, email address,
login name, and password.

The web page should also provide a Submit button that would hypothetically send
the account sign-up request to the (again hypothetical) server. This web page should exhibit the following
behaviros:

(a)Login name and password are required fields;
that is, if they are blank, the Submit button should be disabled.

(b)Password entry should actually consist of two
input type=”password” elements and should implement the typical “please retype
your password” feature of typical account sign-up forms. As with the required fields, the Submit buton
should be disabled if the values in the password fields do not match.:

ANSWER : The program follows:

….

#14. Keyboard input raises
a question: when a key is pressed, which part(s) of a web page should be notified
of the event? Mouse and touch input, by
their very nature, have natural targets: event notification cents on the
location of the mouse or touch event.
Keyboard events do not have as obvious a target.

The concept of focus addresses this issue: at any given tiome, one
specific element, be it a text field, a drop-down menu, a button, or another
element, is designated as the primary recipient of the keyboard events (around
which the event bubblingand captureing cycle takes place). This elementis said to have the focus at that
time. User activities such as mouse
clicks or pressing the Tab key change the currently focused element.

The acquisition and loss of focus are events in their own right:
focus and blur, respectively. Knowing the
element that has keyboard focus has a number of uses, one of which is the
facilitation of context-sensitive help.

Implement a hypothetical user profile page with context-sensitive
help. The page should consist of
multiple labeled text input fields. Next
to each text field, supply a brief explanation of the field that is initially
invisible (i.e. the display style property is set to tnone). Set up appropriate focus and blur event
handlers such that the explanation elements only appear when their
corresponding text field gets the keyboard focus.

ANSWER : The program :