Non mi va via il tooltip ?? dove sbaglio ?

Sulla Root 1° Frame ho inserito

MovieClip.prototype.setTooltip = function(theText, timer, text_color, bg_color, border_color)
{
if (timer == undefined)
{
timer = 500;
}
var addMsg = function (theMsg, col, bg_color, border_color, level)
{
var x = _root._xmouse
var y = _root._ymouse
var f = new TextFormat();
f.font = "Verdana";
f.size = 11;
f.color = col != undefined ? col : 0x000000;
_level0.createTextField('tooltip', 123456, x, y, 150, 20);
with (_level0.tooltip)
{
setNewTextFormat(f);
text = theMsg;
selectable = false;
autoSize = true;
background = true;
border = true;
borderColor = border_color != undefined ? border_color : 0x000000;
backgroundColor = bg_color != undefined ? bg_color : 0xFFFFEE;
_y -= _height;
}
clearInterval(level.q_t);
};
this.q_t = setInterval(addMsg, timer, theText, text_color, bg_color, border_color, this);
};

MovieClip.prototype.unsetTooltip = function()
{
_level0.tooltip.removeTextField();
clearInterval(this.q_t);
};


e sul pulsante

on (rollOver)
{
setTooltip("This is a test comment", 500, 0x000000, 0xFFFFEE, 0x000000);
setTooltip("This is a test comment\nyou can also set multiline text");
}
on (rollOut, release, press)
{
unsetTooltip();
}

Mi dareste una mano ? Grazie