Batch open files, save as new file type

Hi,

I've tried looking on the internet but I'm unable to find much. I'd like a script that allows you to open a selection of PNG files and save them individually as TIFF files with the default settings, under the original PNG name.

So,

Open PNG file '123'

Save as TIFF '123''

Close

Open new PNG file... etc.

Many thanks in advance!