DBI connect('OurDatabase','',...) failed: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified (SQL-IM002)

##</code><code>##

    my $connection 
        = 'dbi:ODBC:driver={SQL Server};'
        . 'Server=OurServer;'
        . 'Database=OurDatabase;'
        . 'Trusted_Connection=Yes'
        ;
    my $dbh = DBI->connect(
        $connection,
        undef,
        undef,
        { RaiseError => 1 }
    );