[SOLVED]Avatar width resize with condition

[danyxxx]

Hello,

I'm looking for a modification like this:

if the avatar width is bigger than 180px -> resize to 180px

How can be made this without affect the width smaller than 180px ???
I try it this way -->

In 'add plugins' ->

PHP Code:

if($post['avwidth'] > '180')
{
  $this->post['avwidth']  = 'width="180"';
} 


But this modification , resize all avatars to 180px .
I want only the avatars that are bigger than 180px to be resized .
Please help because I don't know the language that can be used .... I used ">" for definition "bigger then" but I see that doesn't work .

Kind regards !