form vs href link corrupt - php

Question

So I have been trying to get upload/download system to work but kept running into problems, specifically, the downloaded file being corrupt (.xls).
This is what I have currently:
<form action="{{block type=" core/template" name="my-template"
template="php/download_file.php" }}" method="post">
<label for="date">Date:</label>
<input type="date" name="date" id="date"><br>
<input type="submit" name="submit" value="Download">
</form>
download file
So, these both link to the same file and downloads fine.
If I click on the download file link, file opens perfectly fine.
If I go through the form download button, then it'll download but opening gives me a warning/error: "the file format and extension of 'file' don't match" and just hangs forcing me to force close the file.
download_file.php:
<?php
if($_POST['submit']) {
$file = 'excel_file.xls';
// Magento file path
$path = Mage::getBaseUrl('media') . 'folder' . DS . $file;
header("Content-Type: application/vnd.ms-excel");
//header("Content-Type: application/octet-stream");
header("Content-length: $size");
header("Content-type: $type");
header("Content-Disposition: attachment; filename = 'filename'");
echo $path;
exit;
}
?>
This is all in a Magento Static Block, in case that has anything to do with it.
Any help is appreciated.
Thanks.

Answer 1

Have you tried this:
header("Content-Type: application/vnd.ms-excel; charset=utf-8");
header("Content-Disposition: attachment; filename=abc.xls"); //File name extension was wrong
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false);
Greetings.

Answer 2

Try changing:
header("Content-Disposition: attachment; filename = 'filename'");
to:
header("Content-Disposition: attachment; filename=filename.xls");
Or if you use a variable:
header("Content-Disposition: attachment; filename=$filename.xls");
Basically, start and end with a quote and don't use any quotes or apostrophes in between.