Mobile App to Scan Barcode

I'd like to write an app to read a bardcode, IOW, to be a barcode scanner.

The barcode is on a label at the back of our University books. It's how books are identified within our library management system. It's not the ISBN barcode it's our own book #.

The app should scan this barcode and do some other dialogs (student #/pwd etc) so that students might be able to withdraw the book from the library. The app might even have access to the phone # so that I could verify it at our database to check if the # is corrent and then allow the book withdraw.

The point is :

1) Could I do that using HTML5 only ? Cause I'm very fluent with Web Programming... Also the same app might be running at the desktop for instance. I could have PCs installed at the library so that users might do their registrations (for those who dont want to use the mobile).

2) I'd better do an specific app to be installed on the students mobile phones ? Since I dont know any platform for doing this very likely I'd start with some Python stuff....

Other ideas ?

Thanks in advance !