Export Table in EXCEL with PHP

Question

I am exporting my data to excel format, but when I export the accents do not return correctly, this is my script:

<?php include_once "bancodedados.php"; $table="smt_cadastro_sociedades";
$select = "SELECT * FROM ".$table;                
$export = mysql_query($select);
$fields = mysql_num_fields($export); 
for ($i = 0; $i < $fields; $i++) {
    $header .= mysql_field_name($export, $i) . "\t"; 
}
while($row = mysql_fetch_row($export)) {
    $line = '';
    foreach($row as $value) {                                            
        if ((!isset($value)) OR ($value == "")) {
            $value = "\t";
        } else {
            $value = str_replace('"', '""', $value);
            $value = '"' . $value . '"' . "\t";
        }
        $line .= $value;
    }
    $data .= trim($line)."\n";
}
$data = str_replace("\r","",$data); 
if ($data == "") {
    $data = "\n(0) Records Found!\n";                        
}
else{
    $hoje=date("j_m_Y");              
    header("Content-type: application/x-msdownload");
    header("Content-Disposition: attachment; filename=".$hoje.".xls");
    header("Pragma: no-cache");
    header("Expires: 0");
    print "$header\n$data";  
}?>

Return example: