New to Java

Alright, after starting out for the very first time with HashMaps a few hours ago, I've gotten the hang of them decently I think. I am encountering a problem, though, when I try to get user-selected keys + values to display. My code is:

   public void useZone(String use)
   {
       Object used = hm.get(use);
       System.out.print("\f");
       Set set = hm.entrySet();
       Iterator i = set.iterator();

       if (used != null){
           System.out.println("Time Zone Used:");
           Map.Entry thiszone = (Map.Entry)i.next();
           Object usedzone = thiszone.getValue(); //Get the value of the zones and assign them as Object usedzone
           Integer useval = (Integer) usedzone; //Assign the Object to an Integer value so we can use it
           difference = useval;
           
           if (useval > 0){ //Display the hour offset correctly
               System.out.println(use + ": GMT +" + usedzone.toString());
           }
           else if (useval == 0){
               System.out.println(use + ": GMT");
           }
           else if (useval < 0){
               System.out.println(use + ": GMT " + usedzone.toString());
            }
        
       else{
           System.out.println("Invalid zone name.");
       }
       } //End if
       ClockDisplay.getZone(difference); //Send variable difference
  }

What will happen is that the first time I will be fine...

Say the HashMap keys and values are

"Rome", "-2"
"Chicago", "6"
"New York", "5"
"Paris", "-1"

If I type "Rome" in when I execute this method, it gives me the correct output - "Rome: GMT -2"

If I then re-run the method, as to display a different one, I get "Chicago: GMT -2"

It's like the name the user inputs is updating, obviously, but the value of the HashMap that goes along with the user-input doesn't match up or something. My code is confusing myself after looking at it for nearly 10 hours, so I apologize that I had to post something so trivial here - I'm sure it's just a problem with my wordings....any help would be greatly appreciated.