Over the last several weeks I have introduced HTML to those of you
with little or no experience with it. Hopefully you will now be able
to recognize the basics of an HTML page even if you don't
understand the specifics. It would be even better if you were now
comfortable enough to try your hand at a few lines of code yourself.
I will wrap up this introduction to HTML with a brief introduction
to the use of Forms. Technically speaking, Forms go beyond basic
HTML. They are now so extensively used in so many web pages
however, that they are an integral part on any introduction to HTML.
Forms are used in Web Pages to gather information from visitors.
Anyone that has Surfed the net for even a short while will have
probably attempted to enter information into at least one form. I say
attempted because I am sure a common experience is to spend ten or
more minutes gathering and entering information into a form only
to loose it all. This happens because you selected the wrong button,
entered the wrong information, or attempted to use the form while
the moon was at its zenith during an odd or even hour in any month
that contains a "u", "a" or "e". Any experienced surfer knows this is
certain to cause a problem.
Love them or hate them, forms are here to stay and apt to continue
having problems for the foreseeable future. The reason is that many
forms contain three separate operations. The first of these is the
HTML that actually displays the form. Here is an example that will
not cause a problem.
The reason this form is reliable is because it allows you to enter up
to 30 characters of text but it does not do anything with it. Forms
require two additional components to be useful. The second of these
is an Action to take with the form and the third is a program to
process the incoming data. It is this last one where problems
often occur.
OK, if you look at the source on the Web Page for this example you
will see that it is more extensive than the code here. If you read last
week's newsletter about Tables you should recognize what is going
on. The extra code is used to create a simple table. Forms are an
ideal candidate for tables.
The principle difference between this Form and the previous
example is the Action option in the Form Tag. This will send the
information gathered by the Form to the program formmail.pl.
These are the other two components of a Form which I am sure most
of you have heard of before. The act of transmitting the Form data
somewhere is referred to as CGI for 'Common Gateway Interface'.
Once transmitted, the data must be processed by a program. This
example sends the data to a Perl Script called "formmail.pl" which
will retransmit the user's "Email" address and "Question" to
news@VirtualMechanics.com .
One of the reasons CGI is popular is because it can send data to
almost any program. Perl is the most popular but C, C++ and others
are also often used. It is the program that usually causes the
problems. Most of these programs are custom made for each form.
Alpha and Beta testing is consequently done by the first visitors to
use the form.
In future newsletters I will try to find some interesting forms that
some of you may wish to use on your Web Site. For those of you
that would like to learn more about using forms, here are a few sites
with more detailed information. There are many other.
"IMS Web Tips" is a weekly news letter for all web site managers regardless of experience who are looking for detailed information on
creating, maintaining and promoting their web sites.
