Validating form field
We will also do two more things when the user submits the form: The next step is to create a function that will do all the checking for us (which is much more convenient than writing the same code over and over again). Now, we can check each $_POST variable with the test_input() function, and the script looks like this: Notice that at the start of the script, we check whether the form has been submitted using $_SERVER["REQUEST_METHOD"].
If the REQUEST_METHOD is POST, then the form has been submitted - and it should be validated.
In other web browsers they can be used in combination with the .
Obviously neither example is very limiting, but it will prevent people from entering completely wrong values, such as phone number, strings with multiple '@'s or spaces.
While it would be great to see something like this in every browser, for now you probably need to stick with the ubiquitous Java Script plugins. Arjen, You're correct: and it's not just the plus sign ( ), although I have to admit, I've never seen that used in an email address before.
While the code we're using is slightly more complicated, this should get you started: Some of the articles below, particularly the first two, provide other style/scripting options and solutions for supporting older browsers. Wikipedia has a list of potentially valid email formats here: en.wikipedia.org/wiki/Email_address#Valid_email_addresses Most browsers accept [email protected] as valid for email input as it can be technically correct in some situations - on an intranet for example. How do you only show the fields as 'invalid' after the user leaves (blurs? It's ugly to have ready icons displayed when the page loads.
Be aware of that any Java Script code can be added inside the - this would not be executed, because it would be saved as HTML escaped code, like this: <script>location.href(' The code is now safe to be displayed on a page or inside an e-mail.For a more detailed introduction to HTML5 form validation you can find some great articles linked under References below.