Javascript: Check Internet connection before attempting to run SQL command on remote server

Good evening,

I am developing a form that reads and posts data from/to a table hosted on a remote PC running XP/SQL Server Express 2008 R2. I access the server through the Internet.

My problem is that if the internet connection happens to be down when I -eg- try to save data to the table using the form, the SQL command tries to reach the server for a while, and eventually crashes.

Is there a way to programatically verify that a remote SQL server is reachable over the Internet before attempting to run a command on it?

Many thanks in advance for any help you can provide!

Randy