Is there Data Access Layer (DAL) for JavaScript?

Hello
I am wondering to know if Is there Data Access Layer (DAL) for Javascript or a way to get Data from a DB using Javascript Programatically?
Let me explain, in the Javascript onload Event, depending of the option that the user [size="2"]choose[/size] [size="2"]from a Lookup wizard I need to get a value from a table that is not showing any data on the actual page then calculate something and later let the user continue.[/size]

I know that if I need 1 field of a table I can create a control and hide on the page and according of the user selection update this control but what happen when you need 10 fields of a database according of the user selection?
[size="2"]Please, could you help me,[/size]
[size="2"]Thank you.[/size]