Q:

How to make the "Telephone" field of magento "not required" only for a particular theme?

How to make the "Telephone" field of magento "not required" only for mobile version?
I tried changing "is_required" column of "Telephone" row in "eav_attribute" table. But it changes telephone not required for both desktop and mobile version.
Commenting 
if (!Zend_Validate::is($this->getTelephone(), 'NotEmpty')) {
$errors[] = $helper->__('Please enter telephone.');

in magento/app/code/core/Mage/Customer/Model/Address/Abstract.php also did the same!
Is there any other way to make this work for a particular theme?

A:

I would add a system config field "telephone required" configurable on store view level and perform the telephone validation only for the normal version and not for mobile. This will obviously only work if you have created a different store for mobile.

