Movie Clip starting point problem

how can I get it to start in a different place?

[HelenDev]

I've taken some actionscript off the web to make a movie clip move randomly about the screen. This is good. But it always starts in the top right hand corner, and I want to be able to specify where it starts.

From my brief actionscript reading today it seems that we can set the x co-ordinates using something like this

this._x=500;

But I don't really know what I'm doing (no time to learn!) and wherever I insert it, it doesn't work. Here is the code I'm using...

In frame one of layer 'actions'...

function getdistance (x, y, x1, y1) {
var run, rise;
run = x1-x;
rise = y1-y;
return (hyp(run, rise));
}
function hyp (a, b) {
return (Math.sqrt(a*a+b*b));
}
MovieClip.prototype.reset = function () { 
var dist, norm, movie_height, movie_width;
movie_height = 900;
movie_width = 1200;
speed = Math.random()*4+2;
targx = Math.random()*(movie_width-_width);
targy = Math.random()*(movie_height-_height);
dist = _root.getdistance(_x, _y, targx, targy);
norm = speed/dist;
diffx = (targx-_x)*norm;
diffy = (targy-_y)*norm;
};
MovieClip.prototype.move = function () { 
var cycle;
if (_root.getdistance(_x, _y, targx, targy)>speed) {x += diffx;y += diffy;
} else {x = targx;
y = targy;
if (!this.t) {
t = getTimer();
}if (getTimer()-t>cycle) {reset();
t = 0;
}
}
_x = x;
_y = y;
}

...and on the movie clip itself...

onClipEvent (enterFrame) {
move();
}

Can anyone help?

[HelenDev]

Gave up and did something else instead!