Regular expression validating date
Consider the following: If you are using a supported browser you can use the form below to test the regular expression: If you want to restrict the password to ONLY letters and numbers (no spaces or other characters) then only a slight change is required.Instead of using is shorthand for 'any letter, number or the underscore character'.In most browsers - those that support Java Script 1.5 (Firefox, Chrome, Safari, Opera 7 and Internet Explorer 8 and higher) - you can use more powerful regular expressions. The code presented above is fine in that it checks everything that we wanted to check, but uses a lot of code to test each requirement individually and present different error messages.We're going to show you now how to apply the password tests using a single regular expression.One popular approach is to install Fail2Ban to monitor log files and lock out repeat offendors.
You might also want to spice up your forms using HTML5 Form Validation as we've done further down the page.
If the purpose of registration is to confirm that the person exists, and that they have supplied a valid email address, then as part of the registration processe you a should either email them a random password or a confirmation token rather than letting them choose their own password and use it immediately.
The code presented below would then be used for letting the user change their password.
The red/green markers have been implemented using CSS: In this example it should be clear to the user that the form can only be submitted once all three green ticks appear.
In any case browsers such as Firefox and Opera will enforce the HTML5 validation rules and present messages as shown here: Presumably the browser messages will change according to the users language - something that would never be possible using only Java Script.