Validating Radio Button Groups By setting the value of the variable, "found_it" equal to the checked button's value, the original button loop script can easily find which button was checked. We need a way to handle this situation, especially if you want to require a button from a group be checked.
Before getting into the additional validation scripting, I want you to notice something about the found_it variable in the original script - it is declared but not initialized. Because it was not assigned a value initially, it has an original value of null, and will stay that way unless its value is reset to a checked button's value. Logical operators test two boolean values for equality.
You can also assign other processing tasks that you define in a script.For example, the button might calculate the total cost of items selected based on assigned values.You can create forms that submit data to most application servers, including PHP, ASP, and Cold Fusion.If you use Cold Fusion, you can also add Cold Fusion-specific form controls to your forms. The text can be displayed as a single line, multiple lines, and as a password field where entered text is replaced by asterisks or bullets to hide the text from onlookers.Let's build a simple form with a validation script.
When you submit a form to a CGI program that resides on the server, it is usually programmed to do its own check for errors.If it finds any it sends the page back to the reader who then has to re-enter some data, before submitting again.A Java Script check is useful because it stops the form from being submitted if there is a problem, saving lots of time for your readers.Server-side validation is more secure but often more tricky to code, whereas client-side (Java Script) validation is easier to do and quicker too (the browser doesn't have to connect to the server to validate the form, so the user finds out instantly if they've missed out that required field! In this tutorial we'll build a simple form with client-side Java Script validation.You can then adapt this form to your own requirements.For example, if your form has a box for the user to type their email address, you might want your form handler to check that they've filled in their address before you deal with the rest of the form.