Some help with understanding the way ac3 works.

Hello guys, im new to ac3, and im messing around with it for about a week now.
ill paste my code and then i will explain whats not working, please don't only fix my code, i would like to understand why it not working like i want it to.
My Code:

stop();
var TextCount:int = 1;
addEventListener(Event.ENTER_FRAME , FramePos );

function FramePos (e:Event):void{


  var MyFrame:int = this.currentFrame;
    
  if (MyFrame == 1){
  gotoAndStop(1);
  }
  if(MyFrame == 14){
  gotoAndStop(1);
  }
  if(MyFrame==3){
  TextCount=4;
  }
  my_text.text=("Frame :" + MyFrame + "TexCount is: " + TextCount);
}

o whuy

so i have my var TextCount, is first set to 1, then i say : if MyFrame==3 TextCount=4 , now when i run this, every time it goes to frame 3 textcount becomes 4 , but then when movie clip go back to frame 1, it goes back to be 1.

and i don't understand why, i was thinking that only what goes in enter frame function lunches when it enters a frame, and that other code just lunches once, i see now i was wrong,

how can i write this correctly?

Thanks A head to all people who take there time to read this and try to help.