Modify the example in web_1.zip:

- Add an HTML form that invokes an operation "getBibtex" on server.ol passing the value of an input field called "dblpkey".
- Add an operation, getBibtex, in server.ol that, when invoked, uses the code from dblp_client.ol (feel free to copy what you need from there) to get the Bibtex entry
of a paper with the appropriate dblpkey.

Examples of valid dblpkeys:

books/ph/KernighanR78
books/sp/wsf14/MontesiGZ14