file export woe's

Hello,

I'm hoping someone can help me here.

My problem is this:
I've performed a very simple SQL query, and structured it in a table. at the end of the table I have the option to export the table to excel.

the code for the link is <a href="display.php?export=excel">export to excel</a>

within this page the first line of code is:

<?php
$sExport = @$HTTP_GET_VARS["export"];

if ($sExport == "excel") {
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment; filename=Load.xls');
}


This works FINE - but I have another variable that I pass using GET to determine how to query the database, and populate the table. this code is directly below:

if($_GET['export'] == "nsls"){

//query database based on NSLS sources
db_connect(nsls);

} else if($_GET['export'] == "ms1") {

//query database based on ms1 sources
db_connect(ms1);

} else if($_GET['export'] == "ms2") {


//query database based on ms2 sources
db_connect(ms2);

}

the called function is what determines the contents of the table...

without this code, the export works fine, opening in excel the appropriate data table. as soon as I add this code, my excel document is just a copy of the web page this is on...

What am I missing??

Please let me know if you have any suggestions, or let me know if you need more input.

Thanks very much in advance!