onTweenComplete

hi can you help me with “onTweenComplete”

My problem is

1,
when i press FIRST BUTTON i want to Slide **[COLOR=red]My_mc [/COLOR]**to X position (x position could be for example “0”) and after tween (onTweenComplete)
i WANT to load EXTERNAL.SWF ONLY IF I PRESS FIRST BUTTON

2,
when i press SECOND BUTTON i want to Slide [COLOR=red]My_mc[/COLOR] to NEW X position (x position could be for example “250”)
and NOW i DON´T WANT to load EXTERNAL.SWF onTweenComplete again

EXTERNAL.SWF is still load onTweenComplete when i press **SECOND BUTTON **as well as FIRST BUTTON

[COLOR=red]THIS IS MY BAD CODE[/COLOR]

//FIRST BUTTON
btn_ON.onPress = function() {
My_mc.xSlideTo(0,1, “easeOutExpo”,0, LOAD_EXTERNAL_SWF);
};

//
My_mc.onTweenComplete = function(LOAD_EXTERNAL_SWF) {

trace (“LOAD EXTERNAL.SWF”);

};

// SECOND BUTTON
btn_OFF.onPress = function() {
My_mc.xSlideTo(250,1, “easeOutExpo”);
};

THANK YOU
fstyler

P.S.
sorry for my english