The HTML forms tags mostly tell the browser to add user interface
elements like input boxes, radio buttons and pulldown lists to the web
page. The <FORM> tag is used to tell the browser how
to send the data entered in the form to a program on the server for
The FORM tags are used to group a collection of interface
elements together, and instruct the browser how to send the data back
to a CGI script on a web server for processing. You can have several
forms on a web page, each associated with a different script.
A typical usage is:
The ACTION attribute specifies the name of the processing
script. The value is a URL.
The METHOD attribute specifies the communication protocol
between the browser and the server. There are two options,
POST and GET.
GET -- this is the default method and causes the
fill-out form contents to be appended to the URL as if they were
a normal query.
POST -- this method causes the fill-out form
contents to be sent to the server in a data body rather than as
part of the URL.
The GET method is a bit simpler, but because the data is
transferred using environment variables, there are length
restrictions. POST is also slightly preferable fro
security reasons too.
The input tag currently supports the following data types
(depending somewhat on which client you are using):
For entering a single line of text. The SIZE attribute can be
used to specify the visible width of the field. The MAX
attribute can be used to specify the maximum number of
characters that can be typed into the field.
For entering integers. The maximum number of digits can be
specified with the SIZE attribute.
For Boolean variables, or for variables which can take multiple
values at the same time. When a box is checked, the value
specified in its VALUE attribute is assigned to the variable
specified in its NAME attribute. If several checkbox fields
each specify the same variable NAME, they can be used to
assign multiple values to the named variable, since each
checkbox field may have a VALUE attribute.
For variables which can take only a single value from a set
of alternatives. If several radio buttons have the same
NAME, selecting one of the buttons will cause any already
selected button in the group to be deselected.
Selecting this link or pressing this button submits the form.
Selecting this link or pressing this button resets the form's
fields to their initial values as specified by their VALUE
For passing state information from one form to the next or from
one script to the next.
An input field of type HIDDEN will not appear on the form, but the value
specified in the "VALUE" attribute will be passed along with the other
values when the form is submitted.
For fields which can accept floating point numbers.
Fields which can accept a recognized date format.
For fields which expect references as URLs or URNs.
The RADIO and CHECKBOX fields can be used to specify multiple
choice forms in which every alternative is visible as part of
the form. An alternative is to use the SELECT element which
produces a pull down list. Every alternative is specified in an
Click here to see
how the select list would be rendered by your browser.
You can then use the up- and down-arrow keys to select an option which
will be set when you press enter to leave the pull down menu.
If you include the MULTIPLE attribute in the <SELECT> tag, the
user should be able to select more than one optional value
from the list.
When you need to let users enter more than one line of text,
you should use the TEXTAREA element:
The text between the <TEXTAREA> and
</TEXTAREA> tags is used to initialize the text area
This </TEXTAREA> tag is always required even if the field
is initially blank.