_X and _Y position

Hi all!! Good morning!!

I need to control the X and Y position of some movie clips but it’s not working. This is what I’m doing:

 
i = 1;
my_picture = this._name.substr(0, 9);
**my_X_position = this._x;**
**my_Y_position = this._y;**
while (i<=N_pictures) {
picture = "picture_"+i;
if (picture == my_picture) {
**eval(my_picture)._x = my_X_position; **
**eval(my_picture)._y = my_Y_position;**
eval(my_picture)._alpha = 100;
i = i+1;
} else if (picture<>my_picture) {
eval(picture)._alpha = 0;
**eval(picture)._x = 2000; //I'm sending the movie clip far away**
**eval(picture)._y = 2000;**
i = i+1;
}
}

I put the movie clips with an _alpha = 0 at the beggining in the correct position. When picture = my_picture, the script should put the movie clip at it’s position but instead it puts it somewhere else.

The script is not in the main timeline, everything is inside a symbol. Could this be the problem?, How do I solve this?

Thank you very much in advance!!
Lasbi