if else statement errors

I am practicing php. SO today i am trying to do the image upload with validation. I am getting some problem in validation. here is my code

    <?php 
        if(($_SERVER['REQUEST_METHOD'] == 'POST') && isset($_POST['upload_btn'])){
          if(empty($_POST['up_image'])){
             echo "<p class='bg-danger'>Upload Your Image...!!!</p>";
          } else{
              $permitted = array('jpg','jpeg','png','gif');
              $file_name = $_FILES['up_image']['name'];
              $file_size = $_FILES['up_image']['size'];
              $file_temp = $_FILES['up_image']['tmp_name'];

              $div = explode('.', $file_name);
              $file_ext = strtolower(end($div));
              $unique_name = substr(md5(time()), 0,10).'.'.$file_ext;
              $uploaded_image = 'img/'.$unique_name;

              move_uploaded_file($file_temp, $uploaded_image);
              $insert_img = $user->insert_image($uploaded_image);
              if(isset($insert_img)){
                 echo "<p class='bg-success'>Image Inserted Successfully...</p>";
    }
}    } ?>

when I upload image its return Upload Your Image...!!! when empty this is okay. But its also showing when I insert a image. I tried with removed the validation of empty, then I can successfully upload image. What to do in this case? Help me please.

Thanks in advance.