Why my button in for loop isn't working?

Hi Guys,

I want to have my each new timer with a button created. And when it's pressed, it start to count down.

What the problem is:
In this for loop, each time a new Timer is created with message: `Debug.Log("Countdown START");` is returned instead.
I wanted the message to return ONLY when my Timer's button is pressed.
It's executing the Debug Log count down earlier one step. It isn't inside the if button section.

But I don't know why it didn't work in this for loop.

Below is my coding:

 function OnGUI ()
 {
    GUI.Box(Rect(buttonRect), "NEW TIMER");
 
       for (timer in PlayerTimerList)
       {
           if ( GUI.Button(timer.TimerBox,timer.TimerName) );
            Debug.Log("Countdown START");
              //run function countdown here 
           if (timer.TimerActive)
               {
                   GUI.Label(timer.TimerBox,"!" + timer.TimerRemain);
               }
           
          }         
 }

With for loop in my function OnGUI. The button didn't react as it usually does.

  if (GUI.Button(Rect(10,10,50,50),"WOOO"))
      Debug.Log("Clicked the button with an image");

Please let me know where I have gone wrong in this button with for loop part, thanks!