How to add auto-resizing advertisement images?

[Sono]

I would like to add some CD advertisements to  my forum. I want to place them to the header, about 5 or six in one row, using Simpleportal. I would add a custom HTML block and embed image links there. However, when I tried it earlier, I had a problem that as the width of the forum varied from device to device, the size of the photos didn't change and it happened that on the sides parts of the images were not visible, if the forum was set quite narrow on a device. How to overcome this problem, and force devices to resize the images along with the forum? Can anyone suggest a solution?

[Hj Ahmad Rasyid Hj Ismail]

If that is not a javascript and simply images with links, IMO that would require advanced css tricks. Google up css @media tricks. Maybe that would help.

[Sono]

I don't mind even if it is a Javascript.