Slideshow on Mobile isn't resizing

Excusez moi! But I don't understand. What is the extra of de slides manager? The parameters show the possibility to load images specially for Mobile with a prefix.
The names of the images are the same as the originals, and uploaded in a file named 480 as mentioned.

Please explain.

just to make a test, I know how the code works
just make a little test please. If this does not work I will need a ftp access

Sorry! Ok therefor I'll need to download and install the plugin Slideshow params??

no... you wrote

Import from folder (images/480/example.jpg)!

this means that you are using the plugin params. The slides manager that I ask you to test is natively in the module

the easyest would be to contact me per email and give me an admin and FTP access to check

ok I have checked your website
1/ my bad, I was looking at the top slideshow (even if you have told to look at the bottom one
2/ the system is working, regarding the source of the image under 480px page width it loads

/projecten/welland/site/images/480/ad_01.png?1399372928421

3/ you have set up the slideshow with some fixed values in PX, I have changed this for "auto" width and it looks better

just to be clear, you must resize your browser under 480px, then refresh the page and the new image will be taken
CEd

That works!! Thanks a million!