Combine the following sentences without changing the meaning.

I was sleeping in my hotel room. There was a loud bang on my door.

→ .............................

I was sleeping in my hotel room when there was a loud bang on my door./When there was a loud bang on my door, I was sleeping in my hotel room./There was a loud bang on my door while I was sleeping in my hotel room./While I was sleeping in my hotel room, there was a loud bang on my door.