ASK: Animation by Script (AS2)

I’m using Flash CS4 as2. I have 2 movieclips, i want to animate them by some script as follow.
//==bof===
function tweenFlow1() {
easeType = mx.transitions.easing.None.easeNone;
var begin = 100;
var end = 200;
var time = 1;
var mc = Flow1;
Execution = new mx.transitions.Tween(mc, “_x”, easeType, begin, end, time, true);
}
function tweenFlow2() {
easeType = mx.transitions.easing.None.easeNone;
var begin = 300;
var end = 400;
var time = 2;
var mc = Flow2;
Execution = new mx.transitions.Tween(mc, “_y”, easeType, begin, end, time, true);
}
myBtn.onRelease = function() {
tweenFlow1();
if(Flow1._x==200)
{
tweenFlow2();}
};

//==eof===
The target script above is to animate mc “Flow2” after mc “Flow1” done, but i don’t know why in that script the mc “Flow2” is not running. Anything mistake on that script ??? Or any other advice ??? Please help !!!