Latest Items from individual categories- home page

[Horizon]

The default recently added content block has the code:

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I want to show the newest 4 ads from the category with ID 623, so I created a new content box as follows:

type: php

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but it doesn't limit it to the category with id 623, it still shows recent listings from all categories.

Is there something else I should enter in this block to make it show the recent listings only from category 623?
Or do I have to still do a code modification to make this work as in earlier years?

[Horizon]

Any tip on using a content block to show images from only one category? I must be missing something in the post above, but I can't see it even after looking at it for an hour. Have a feeling it is something simple that I'm not seeing

[Rudi]

Go to plugins/listings_box/rlListingsBox.class.php > public function getListings

after:

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add:

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[Horizon]

Fantastic! Works great. Thank you Rudi!