pass a random generated variable to setInterval

I have animated a dynamic created element with setInterval. When the element is clicked I want it to change to a random direction (left, right, up or down).

I think the problem is that I can´t pass the randomly created direction into the setInterval function.

The html here....

<div id="klicker"></div>

The JavaScript here.....

var box = document.getElementById("klicker");
var x = 1;
var startp = 200;
box.onclick = function() {
    var newdiv = document.createElement('div');
    document.body.appendChild(newdiv);
    newdiv.style.width = 200 + 'px';
    newdiv.style.height = 200 + 'px';
    newdiv.style.backgroundColor = 'grey';
    newdiv.style.position = 'absolute';
    newdiv.style.left = startp + "px";
    newdiv.style.top = startp + "px";
    newdiv.setAttribute('id', 'runner')
    var run = document.getElementById('runner');
    var dire = 'right';
    run.onclick = function() {
        var mov = function() {
            randoms();
        };
        function randoms() {
            alert('ddddd');
            var rnd = (Math.random() * 4) + 1; //ranom number 1-4
            var rnd_down = Math.floor(rnd); //make it en integer
            /*--- make each number a uniqe direction---*/
            if (rnd_down == 1) {
                dire = 'right';
            } else if (rnd_down == 2) {
                dire = 'left';
            } else if (rnd_down == 3) {
                dire = 'up';
            } else {
                dire = 'down';
            }
        };

        var moveit = setInterval(function() {
            movefunc();
        }, 50);

        function movefunc() {
            /*----each direction will make the div travel in diffrent directions--*/
            if (dire = 'right') {
                x = x + 1;
                newdiv.style.left = x + 'px';
            } else if (dire = 'left') {
                x = x - 1;
                newdiv.style.left = x + 'px';
            } else if (dire = 'up') {
                x = x - 1;
                newdiv.style.top = x + 'px';
            } else {
                x = x + 1;
                newdiv.style.top = x + 'px';
            }
        };
    };
}