title: Firebase Storage Overwriting Files
body: <p>I have small bug in my program.</p>
  
  <p>I have firebase Storage in my app. I wanna let the user to upload image to the storage.</p>
  
  <p>the thing is when the user uploads image and then tries to upload another image. what the program does it overwrites the image was uploaded before.</p>
  
  <p>what I want is to avoid "overwrite" when the user wants to upload another image. and keep both images in different file</p>
  
  <pre><code>let currentUser = Auth.auth().currentUser
      let StorageRefrenece = Storage.storage().reference()
      let posterImageRef =
          StorageRefrenece.child("posters").child(currentUser!.uid).child("posterOne.jpg")
  </code></pre>
  
  <p>Thnx</p>