Forum Upload manager
 

Question about uploading images.
In the attachmentsmanager i click the "+ add files" button. Then it shows up "+ upload" so you can add one and one image, but one time i clicked it, it opened a box where i could mark and upload 100+ images from my computer in one click.
I cant figure out how i did this, so my question is:
Where can i find the settings for this so it will enable for easy mass upload of images in posts?