how to detect if a jpeg file is progressive or not

["H.S." <hs.samix@gmail.com>]

Hello,

I have searched google but haven't found an answer I was looking for. I
want to upload some family pics to share among relatives. Some have
dialup connections. To facilitate image downloads in their browsers, I
want to upload progressive jpegs. How do I find out if the jpegs I
already have are progressive or not? If they are not, how do I convert
them to progressive jpegs?

I have:
ii imagemagick   6.2.4.5-0.8


->HS