Masalah gambar [edit & delete]

//==> Edit : Pada saat saya mengedit berita(content) yang ada gambarnya tampilan gambar ada tapi di inputan file tidak ditemukan.. Jadi jika saya ingin mengedit harus mengupload ulang gambar. Contoh kasus seperti gambar dibawah :

Ini script saya :

<?php
		require_once 'header.php';

	   	$id    = $_GET['id'];

	  	if (isset($_GET['id'])) {
	    $berita   = tampilkan_berita_per_id($id);
	    while($row = mysqli_fetch_assoc($berita)){
			$judul  = $row['judul'];
			$isi    = $row['isi'];
			$gambar = $row['gambar'];
			$tag    = $row['tag'];
			$sumber = $row['sumber'];
	    }
	  }

	?>
	<section class="container-fluid sectionadmin">
		<div class="row">
			<div class="col-lg-2">
				<?php include 'navigasi.php' ?>
			</div>
			<div class="col-lg-10">
				<aside  class="htabelberita">
					<?php include 'heanav.php' ?>
					<br>
					<img src="../images/icons/berita.png" alt="" class="iconadmin">
					<h3>Edit Berita</h3>
					<div class="bdtabelberita">
						<div class="cleaner_h1"></div>
						<form name="frm-berita" id="formberita" method="post" action="" enctype="multipart/form-data">
							<div class="form-group">
			                    <label class="col-sm-2" for="fjudul">Judul :</label>
			                    <div class="col-sm-10">
			                    	<input value="<?= $judul; ?>" type="text" name="judul" id="fjudul" maxlength="150" placeholder="Judul Berita" style="width:100%;" class="form-control1 col-sm-8" autofocus><br><br>
			                    </div>
		                    </div>
							<div class="form-group">
			                    <label class="col-sm-2" for="fisiberita">Isi Berita :</label>
			                    <div  class="col-sm-10">
			                    	<textarea type="text" id="fisiberita" name="isi"><?= $isi; ?></textarea><br>
			                    </div>
		                    </div>
							<div class="form-group">
			                    <label class="col-sm-2" for="fisiberita">Gambar :</label>
			                    <div  class="col-sm-10">
			                    	<img src="../images/berita/<?= $gambar; ?>" id="uploadPreview" class="img-thumbnail" style="width:180px; height:120px;"><br><br>
			                    	<input id="uploadImage" type="file" name="gambar" onchange="PreviewImage();" value="../images/berita/<?= $gambar; ?>"><br>
			                    </div>
		                    </div>
							<div class="form-group">
			                    <label class="col-sm-2" for="ftag">Tag :</label>
			                    <div  class="col-sm-10">
			                    	<select name="tag" class="form-control1" id="flevel">
					                    <option value="Seputar Pampang">Seputar Pampang</option>
					                    <option value="Umum">Umum</option>
					                </select>
			                    </div>
		                    </div>
		                    <div class="cleaner_h15"></div>
							<div class="form-group">
			                    <label class="col-sm-2" for="fsumber">Sumber Berita :</label>
			                    <div class="col-sm-10">
			                    	<input value="<?= $sumber; ?>" type="text" name="sumber" id="fsumber" maxlength="255" placeholder="Misalnya : http://beritakota.co.id..." style="width:90%;" class="form-control1 col-sm-8" autofocus><br><br>
			                    </div>
		                    </div>
		                    <div align="center">
								<button type="submit" class="btn btn-success" name="save"><i class="glyphicon glyphicon-floppy-saved"></i> Simpan</button>
								<button type="reset" class="btn btn-danger" onclick="resetsuratmasuk()"><i class="glyphicon glyphicon-refresh"></i> Batal</button><br><br>
							</div>
						</form>
					</div>
				</aside>
			</div>
		</div>
	</section>
	<?php
		include 'footer.php';
 		if (isset($_POST['save'])) {
			$judul        = $_POST['judul'];
			$isi          = $_POST['isi'];
			$time         = time();
			$gambar       = $_FILES['gambar']['name'];
			$errorgambar  = $_FILES['gambar']['error'];
			$sizegambar   = $_FILES['gambar']['size'];
			$lokasigambar = $_FILES['gambar']['tmp_name'];
			$formatgambar = $_FILES['gambar']['type'];
			$namagambar   = '../images/berita/'. $gambar;
			$tag          = $_POST['tag'];
			$sumber       = $_POST['sumber'];
			$waktuinput   = date('Y-m-d');
			$penulis      = $_SESSION['fullname'];
			if ($errorgambar == 0) {
				if ($sizegambar < 2000000) {
					if ($formatgambar == 'image/jpeg') {
						if (file_exists($namagambar)) {
							$namagambar = str_replace(".jpg", "", $namagambar);
							$namagambar	= $namagambar. "_". $time . ".jpg";
						}

						move_uploaded_file($lokasigambar, $namagambar);

						if (edit_berita($judul, $isi, $gambar, $tag, $sumber, $waktuinput, $penulis, $id)) {
					         echo '<script>
					                swal({
					                  title: "Data Berhasil Diedit",
					                  type: "success",
					                  showCancelButton: false,
					                  confirmButtonColor: "#5cb85c",
					                  confirmButtonText: "Okay!",
					                  closeOnConfirm: false },
					                function(){
					                  window.location = "index.php"; });
					                </script>';
				        } else {
				          $error = 'Ada masalah saat menambahkan data';
				        }

					}else{
						echo '<script>
							swal("Oops...", "Format Gambarnya Harus Jpeg", "error");
						</script>';
					}
				} else {
					echo '<script>
							swal("Oops...", "Ukuran Filenya Kebesaran Maximal 1mb Risize Dulu Yah", "error");
						</script>';
				}
			}else{
				echo '<script>
					swal({
						title: "Gambar Tidak Boleh Kosong",
						type: "error",
						confirmButtonText: "Okay!",
					});
				</script>';
			}
    	}
	?>

//==> Hapus : Nah pada saat menghapus juga gambar yang ada di folder masih tetap ada, tapi di dtabase sudah terhapus Ini scriptnya :

<?php
	require_once "../core/init.php";
	if (isset($_GET['id'])) {
		if (hapus_berita($_GET['id'])){
			header('Location: berita.php');
		}
		else echo 'Gagal menghapus data';
	}
 ?>

function hapus_berita($id){
		$query = "DELETE FROM berita WHERE id=$id";
		return run($query);;
	}

Mungkin ada yg bisa kasih masukan, saya sangat2 berterima kasih sebelumnya agan2.