使用PHPExcel_IOFactory :: load（$ file）不存在文件

I am trying to import excel file using library PHPexcel, but when choosing file and submitting it, it fires Error : Unable to load the file : "1.xlsx": Could not open 1.xlsx for reading! File does not exist... why? can you help plz!

here is code:

<form name="import" method="post" enctype="multipart/form-data">
    <input type="file" name="file" /><br />
    <input type="submit" name="submit" value="Submit" />
</form>

and:

    <?php
error_reporting(0);
include 'Classes/PHPExcel/IOFactory.php';

if(isset($_POST["submit"]))
{ 
    $name = pathinfo($_FILES['file']['name'], PATHINFO_FILENAME);
    $ex = pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION);
    $filename = $name. '.' .$ex;

    try {
    $objPHPExcel = PHPExcel_IOFactory::load($filename);
    } catch(Exception $e) {
    die('Error : Unable to load the file : "'.pathinfo($_FILES['file']['name'],PATHINFO_BASENAME).'": '.$e->getMessage());
    }
}
?>

if i want to write the file path instead of $filename and the file in the project itself, what can i write?