Problem with append += text in Text Field

Question

Hi guys
i have a problem with append text.
I have one array which contain some city names, like CityArea=["NAME 1", "NAME2" ...etc];
Then i have one String and one Text Field.
Using for loop im getting right results. But when im running script again then im getting  same text again.
F.ex.
First time:
City name: Name 1
City name: Name 2
Second time:
City name: Name 1
City name: Name 2
City name: Name 1
City name: Name 2
I have tried to make TextField to and String to Null and delete it, but it's appearing again.. :/
How to avoid this?
Here is script:
for (var i1:int = 0; i1 < CityArea.length; i1++)
  _CityAreaString1 += "<P ALIGN='LEFT'><FONT FACE='Verdana' SIZE='32' COLOR='#ffffff'>        "+CityArea[i1]+"</FONT></P>";
  _CityAreaString1 += "<P ALIGN='LEFT'><FONT FACE='Verdana' SIZE='5' COLOR='#ffffff'><BR></FONT></P>";
_CityAreaTF1 = new TextField();
  _CityAreaTF1.border = true;
  _CityAreaTF1.wordWrap = true;
  _CityAreaTF1.multiline = true;
  _CityAreaTF1.selectable = false;
  _CityAreaTF1.antiAliasType = AntiAliasType.ADVANCED;
  _CityAreaTF1.name = "CityAreaTF1";
  _CityAreaTF1.embedFonts = true;
  _CityAreaTF1.htmlText = _CityAreaString1.toUpperCase();

Answer 1

I think i found why.
There was no problem with TextField.
There was a problem with Array. "CityArea"
So each time I executed script it added new string in Array. And that is because i got like:
TextField
City 1
City 2
City 1
City 2
Running this script is Ok:
for (var i1:int = 0; i1 < CityArea.length; i1++)
  _CityAreaString1 += "<P ALIGN='LEFT'><FONT FACE='Verdana' SIZE='32' COLOR='#ffffff'>        "+CityArea[i1]+"</FONT></P>";
  _CityAreaString1 += "<P ALIGN='LEFT'><FONT FACE='Verdana' SIZE='5' COLOR='#ffffff'><BR></FONT></P>";
But outside of this for loop there is another for loop for adding Cities in CityArray.
I fixed it by adding empty array at the start of function
function myFunc():void
CityArea = [ ]; // Empty array fixed this issue
// LOOP FOR ADDING SHOPS IN CITY AREA
for (var j:int = 0; j < _Shops; j++)
CityArea.push(_Shop);
// FOR LOOP TO ADDING SHOPS IN STRING
for (var i1:int = 0; i1 < CityArea.length; i1++)
  _CityAreaString1 += "<P ALIGN='LEFT'><FONT FACE='Verdana' SIZE='32' COLOR='#ffffff'>        "+CityArea[i1]+"</FONT></P>";
  _CityAreaString1 += "<P ALIGN='LEFT'><FONT FACE='Verdana' SIZE='5' COLOR='#ffffff'><BR></FONT></P>";
Thank you for your help kglad