When using form variables in an action page, keep the following guidelines in mind:
  - A form variable is available on the action page and pages that it includes.
 
  - Prefix form variables with "Form." when referencing them on the action page.
 
  - Surround variable values with number signs (#) for output.
 
  - Variables for check boxes, radio buttons, and list boxes with size attributes greater than 1 only get passed to the action page if you select an option. Text boxes, passwords, and textarea fields pass an empty string if you do not enter text.
 
  - An error occurs if the action page tries to use a variable that was not passed.
 
  - If multiple controls have the same name, one form variable is passed to the action page with a comma-delimited list of values. 
 
  - You can validate form variable values on the client or the server.