无法更新输入类型文件值

1)i am adding image and its title in database but if i submit form for first time it works but again without selecting the image when its pre selected from first submit

2) submiting form 2nd time takes image value null or is empty(updating image)

<form  method="post" enctype="multipart/form-data">
<div id="photoselect_box">
<h5 id="logo_head">Profile Image</h5>
<script>
function profile_imagee(input){
$('#profile_image')[0].src = (window.URL ? URL :webkitURL).createObjectURL(input.files[0]);
}
</script>
 //input image preview
<img src="<?php $path = "download/items/$uid/"; echo $path.$userRow['profile_image']; ?>" id="profile_image" alt="profile photo"  name="profile_image" />


<input type="file" id="img_file" name="profile_image" onChange="profile_imagee(this);"
 value="<?php echo $userRow['profile_image']; ?>" />

</div>

// i am able to update this input after clicking submit
<input type="text" id="download_content1"  name="download_content1" value="<?php echo $userRow['download_content1']; ?>" >

</form>

i cannot update the image value in database after submiting form for 2nd time php code

include_once '../../database/conn.php';
$res=mysqli_query($bd,"SELECT * FROM organisation);
$userRow=mysqli_fetch_array($res); 
$email=$userRow['email'];

if (isset($_POST['register'])){


//inserting  logo  image
$profile_image=$_FILES['profile_image']['name'];
$profile_image_temp=$_FILES['profile_image']['tmp_name'];
// changing the destination required folder according to users unique id
$path = "download/items/$uid/";
@mkdir($path, 0666, true);  // Create  upload folder.
move_uploaded_file($profile_image_temp,$path.$profile_image);



 //updating image in database
 $insert="UPDATE organisation SET profile_image= '$profile_image',download_content1 = '$download_content1 '
 WHERE email = '$email'";

$insert_pro = mysqli_query($bd,$insert);
}