pre_form: Feature to pre-fill form parameters when opening a specific site.

It is convenient for sites that you visit often, but it may introduce
some security issues.  Be careful when using this feature, especially `submit'
params described below.

Default configuration file for pre_form is ~/.w3m/pre_form.

The syntax of entries in the configuration file is as follows:

url       <url>|/<re-url>/
form      [<name>] <action>
text      <name>  <value>
file      <name>  <value>
password  <name>  <value>
checkbox  <name>  <value>  [<checked>]
radio     <name>  <value>
section   <name>  <value>
submit   [<name> [<value>]]
image    [<name> [<value>]]
textarea  <name>
<value>
   :
/textarea

If <action> is set, a form which has matched <action> attributes
will be configured by this pre_form.

A line beginning with text, file, passwd, select, textarea means that
it will set value to <value> in input, select or textarea element which 
name  attribute matches with <name>.

A line beginning with checkbox, radio means that it will check
input element which name and value attribute matches with <name> and <value>
respectively.  If <checked> is 0, no, or off, the checkbox will be unchecked.

A line beginning with submit or image means that it will submit input
element whose name attribute matches with <name> (and value attribute
matches with <value>), or submit on the last <input type=submit> element if no
<name> was specified.

You quote \, ' (single-quote) or " (double quote) as you do in shell.