How to edit order form to prefix domain field with www, or edit message "The domain you entered is not valid" with warning to remove www from domain

[Steve75]

On my order form, if a customer orders hosting and elects to use their own domain if they enter www.example, in the domain name field, and com in the TLD field, they get a warning 

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The domain you entered is not valid

How do I prefix the domain field with a non-editable "www", or adjust the message "The domain you entered is not valid' to tell the customer not to include www in their domain name?

[WHMCS Anwar]

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... or adjust the message "The domain you entered is not valid' to tell the customer not to include www in their domain name?

Hi there,

The message may be adjusted by using a Language Override.

To see what other strings you could override, please check the main language file for that language.
eg. ~/lang/english.php

We do not recommend you modify this file directly. Instead create a language override file:

For an English language override, you would create the overrides folder and in there create a new english.php file as follows ~/lang/overrides/english.php with the following:

<?php
$_LANG['ordererrordomaininvalid'] = "The domain you entered is not valid";

You would simply change the "The domain you entered is not valid" text, to something else of your choosing.  Of course, you may need to do this for every language, if you wanted to be consistent.

More information along with step-by-step instructions is available in our online documentation at
https://developers.whmcs.com/languages/overrides/