Delivery Options in Checkout

I am creating a store where a lot of the orders will be collect from store. I think that it is a bit confusing that when checking out the two default options under Delivery Details are use existing address or add a new one. If the customer is opting to collect then neither of these apply. I want to add a third option "Collect from store".

I have added the following to the top of 'catalog>view>theme>default>template>checkout>shipping_address.tpl':

<div class="radio">
<label>
<input type="radio" name="shipping_address" value="existing" checked="checked" />
<?php echo $text_store_collect; ?></label>
</div>

and changed

<div class="radio">
<label>
<input type="radio" name="shipping_address" value="existing" checked="checked" />
<?php echo $text_address_existing; ?></label>
</div>

to

<div class="radio">
<label>
<input type="radio" name="shipping_address" value="new" />
<?php echo $text_address_existing; ?></label>
</div>

In 'catalog>language>en-gb>checkout>checkout.php' I have added a new line:

$_['text_store_collect'] = 'I want to collect from store';

But I get the following error message:

Notice: Undefined variable: text_store_collect in /var/www/vhosts/omdtakeaway.co.uk/httpdocs/catalog/view/theme/default/template/checkout/shipping_address.tpl on line 6

Any ideas please

you should define it in controller file..
$data['text_store_collect'] = $this->language->get('text_store_collect');
that's all

Good luck

Excellent, thank you