Validating a web form in php
As shown above, once you've added HTML5 attributes to your form elements, they can be easily styled using CSS so that each input field is clearly marked as valid or invalid. If you want something more restrictive you can add a 'pattern' attribute. thx Safari doesn't display any HTML5 validation messages, but it may prevent the form from submitting if any "required" fields are left blank. The red/green symbols are applied using CSS and do work in Safari, but are only an indication of whether the input for that field is valid.input field: This solution is still more complicated than it needs to be as it requires two extra images to be loaded. You forgot the most important part: by having these standard types to identify the fields, browsers can provide helpful autofill interfaces.The simplest change you can make to your forms is to mark a text input field as 'required': This informs the (HTML5-aware) web browser that the field is to be considered mandatory.Different browsers may mark the input box in some way (Firefox 4 Beta adds a red box-shadow by default), display a warning (Opera) or even prevent the form from being submitted if this field has no value.Hopefully these behaviours will converge in future releases.For these examples we have created our own valid/invalid CSS formatting to override the browser default. That's why you may see something like the following: Before you type anything into the box a red marker is shown.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.
Other HTML5 input types include: -related options do have an effect at least in Opera, with pop-up calendars and other devices appearing to assist with input. But as you see, lots of strange looking URLs are actually valid.The following Java Script, placed or included at the end of the page, should enable support for the If you want email validation with RFC 5322 standard: \A(? 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.As mentioned above, we can improve on this by making use of the are already implicit so the input has to match the entire expression. If anyone wants to contribute a more thorough expression to test for valid email or url format, feel free to post it using the Feedback option above.. Since it is not possible to recurse when using a regular expression it is also not possible to create a truly accurate regex for doing email address validation.The value, clicking 'down' with the input blank will result in a very large number. The examples posted in these responses are vastly oversimplified when compared against reality.