Free asian adult web chat Validating when the user submits the form

The HTML form we will be working at in these chapters, contains various input fields: required and optional text fields, radio buttons, and a submit button: The validation rules for the form above are as follows: This code adds a script tag and an alert command.

For example, a text input that only needs to have a value if a checkbox is checked: Using simple logical operators and the functions supplied above you can do all sorts of client-side form validation.To take things a step further you can even explore Ajax Form Validation which lets you supply real-time feedback using server-side scripts triggered by Java Script events.Radio buttons are implemented as if they were an array of checkboxes.To find out which value (if any) has been selected, you need to loop through the array until you find which one has been selected: defines a locally scoped variable.If it has not been submitted, skip the validation and display a blank form.

However, in the example above, all input fields are optional.When the form is submitted - either by hitting Enter or clicking on the Submit button - the to abort (cancel) the form submission. In a real-life situation you will most likely have more fields to check, and more complicated conditions, but the principle remains the same.All you need to do is extend the command, in which case the form will be submitted.User-submitted data should also be verified using a secure server-side script.Otherwise a browser with Java Script disabled, or a hacker trying to compromise your site, can easily by-pass client-side validation.The script works fine even if the user does not enter any data.