When the form is submitted - either by hitting Enter or clicking on the Submit button - the (the 'value' of the field called 'input' belonging to the form). In a real-life situation you will most likely have more fields to check, and more complicated conditions, but the principle remains the same.Other form values are available using a similar syntax, although this becomes more complicated if you're using SELECT lists, checkboxes or radio buttons (see below for examples). All you need to do is extend the command is encountered, execution of the function is halted.In other words if the first condition fails, the second condition will not be tested and so forth.Only when all conditions have been satisfied do we reach the command, in which case the form will be submitted.You can then adapt this form to your own requirements.Let's build a simple form with a validation script.
Also we have included two checklists, respectively labeled as sex and language.
There are two main methods for validating forms: (usually done using Java Script).
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.
Form validation is the process of checking that a form has been filled in correctly before it is processed.
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.