Again, not very helpful, but it will stop people trying to input their email address or other such nonsense. Careful examination of the RFCs associated with email addresses has been conducted repeatedly and has been proven to require the use of recursion in order properly determine the validity of an email address using the full set of RFC specifications.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.In this article we intend to present only a number of simple examples to get you started, covering the basic form elements.Before you ask, and someone always does, these examples will currently work in the following browsers: Safari 5, Chrome 6, Opera 9, Firefox 4 Beta and the i Phone/i Pad.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.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.
List of controls that can be set as required fields The following table lists the TE000130087 controls that can be set as required, and indicates whether each control is available for browser-compatible form templates.
By selecting this check box, you make the field for the control a required field.
The option of using pure HTML, sometimes with a touch of CSS, to complement Java Script form validation was until recently unthinkable.
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.
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.