How to change OS Property captcha to numbers only

I am trying to change the current component captcha from letters/numbers mix to numbers only.
I looked in the component files and it has a folder named .../components/com_osproperty/captcha. But this folder only has 2 files (background image and index.html file).
Where can I find the path to the file that allows me to change captcha configuration?
Thanks.

Hi,
To change the captcha from letters to numbers only. Please follow these steps
1. Open file: components > com_osproperty > classes > listing.html.php
2. find
$RandomStr = md5(microtime());// md5 to generate the random string
$ResultStr = substr($RandomStr,0,5);//trim 5 digit
$row->ResultStr = $ResultStr;
and replace by
$row->ResultStr = rand(10000,99999);
Good luck
Dam

Thank you, this changed the captcha in "Request More Detail" in individual listing view.
How about captcha for company and agent registration?

(P.S.: The code to change captcha for individual listing is in line 1794 of the file)

Hi,
With agent registration, please follow these steps
Open file : components > com_osproperty > helpers > agentregistration.php
find
$RandomStr = md5(microtime());// md5 to generate the random string
$ResultStr = substr($RandomStr,0,5);//trim 5 digit
and replace by
$ResultStr = rand(10000,99999);

With company registration, please follow these steps
find
//Random string
$RandomStr = md5(microtime());// md5 to generate the random string
$ResultStr = substr($RandomStr,0,5);//trim 5 digit

and replace by
$ResultStr = rand(10000,99999);
Good luck
Dam

The correct location to change the captcha code is:

Agent Registration: components > com_osproperty > helpers > layouts >agentregistration.php
Line: 217

Company Registration: components > com_osproperty > helpers > layouts >companyregistration.php
Line: 163

Request More Detail (Listing View): components > com_osproperty > classes > listing.html.php
Line: 1794

Thank you.