获取错误mysql_field_name（）期望参数1是用于将Mysql导出到Excel的资源

I'm trying to export my MySQL query to MsExcel using PHP script, one execution of script I'm getting the following error:

Warning: mysql_field_name() expects parameter 1 to be resource, object given php file on line 161

The data is exporting, but headings (field names of the mysql of the table) are not exporting. Also, I expected to have every field on a separate cells, but its saved each row in one cell.

Here is the PHP Script:

$data = '';
$header = '';

$result = mysqli_query($GLOBALS['mysqli'], $export_sql) or die ("<b>Couldn't execute SQL query:</b> " . mysqli_error($GLOBALS['mysqli']));

$fields = mysqli_num_fields($result);

for ($i=0; $i < $fields; $i++) {
    $header .= mysql_field_name($result, $i). "\t";    // line 161
}

while ($row = mysqli_fetch_row($result)) {

    $line = '';
    foreach ($row as $value) {

        if ((!isset ($value)) || ($value == "")) {
            $value = "\t";

        } else {
            $value = str_replace('"', '""', $value);
            $value = '"'.$value.'"'."\t";
        }

        $line .= $value;
    }

    $data .= trim($line). "
";
}

$data = str_replace("", "", $data);

if ($data == "") {
    $data = "
(0) Records Found!
";
}

header ("Content-type: application/octet-stream");
header ("Content-Disposition: attachment; filename=Export.xls");
header ("Pragma: no-cache");
header ("Expires: 0");
print "$header
$data";

Any suggestions to resolve the problem?