first off if you are going to use CGI you might as well use it to print the header..

#!perl -w
#  ^  you may need that first line 
# my local Apache server does...

use DBI;
use CGI qw/:standard/;

print header;
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Also take out use DBD::ODBC; it's nota module you need to import. it's a driver. generally just use DBI. You may Need to Set up a "System DSN" connection to the SQL Server in Conrol Panel->Data Sources(ODBC). and you will have to declare a value for $DSN. Also make sure that the driver for SQL Server is in you list of Drivers in the Same ODBC Panel