I am writing a web-based library system. I would like to use barcode scanner
to read the readers and the books information for loan and return procedure.
But I have no idea for the coding. Could you please suggest any solution
about this topic?
Thank you very much !

Gladys

If you use a keyboard wedge scanner, the data from the barcode will
appear on the screen at the cursor location... just like you typed it.
 There is no special coding required.  The data will be plain text,
whatever information was encoded in the barcode.

Here is a little info about scanners and interfaces:
http://www.makebarcode.com/scanners/scaninterfaces.html

Bob Lounsbury
The Barcode Software Center
www.makebarcode.com