Accessing SQL Server from Browser Safely and Portably

Dear JavaScripters:

I wish to access an SQL Server database. I want this to work
with more than just IE so the use of ActiveX on the browser side is
out. On the server-side, I do not care for now though if it is
avoided there, too, fine.

I want something like this use case (to start):

User:
Specify that Client ABC's row is to be retrieved.

Browser-Side:
Receive user's request.
Open XHR connection.
Send request to get Client row for Client "ABC".

Server-Side:
Receive request.
Translate it (this example) to "execute GetClientRow 'ABC'".
Send that translation to SQL Server.

SQL Server:
Execute the SP and return the results.

Server-Side:
Get the results.
Send them back to the browser.

Browser-Side:
Get the results.
??? What format? And how do I access the data?
Fill in the DE form with retrieved data.
Do data entry stuff.

I repeat: I do not want ActiveX on the browser-side since I want
this to work with more than IE.

I thought it should be easy to find some basic code for this, but
no such luck.

The above use case implies changing the data and updating the row
and naturally, I want to be able to do more. Being able to do the
above would be a good start. My opposite number is unlikely to allow
adding additional software (Node.js, for example) on the server.

How do I do this?

Sincerely,

Gene Wirchenko