Going only _x in Random Movement

Hi Guys,
Does anyone know how to change the below code to only move randomly along the _x axis and NOT the _y axis?

I’m not sure what to change…

Thanks so much.

//Random Movement: kirupa.com
//Thanks to Suprabeener for the original code!

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(aa+bb));
}
MovieClip.prototype.reset = function () {
var dist, norm, movie_height, movie_width;

// movie_height: refers to the height of your movie
// movie_width: refers to the width of your movie

//---------------------------------

movie_height = 550;
movie_width = 400;

//---------------------------------

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;

// cycle: specifies speed of the movement. The smaller
// number, the faster the objects move.

//--------------------------------------------

cycle = 100;

//--------------------------------------------

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;
}

Bah! I got it!

Incase anyone is interested, i set the movie_height = 1;

It was much easier than I thought…