What can I expect from an HTML dropdown box in passing data? Using JavaScript, you can expect universally to most browsers, a minimum of 3 pieces of data. There are ways to extract and pass more data, as well as use additional indexes but not all browsers support them.

sea zero sea one sea two sea three sea four

selectedIndex
options[].value
options[].text

selectedIndex Demo

View the source. This routine demonstrates what you can expect and what values you can pass from an HTML dropdown box and JavaScript.