Animation not running

I'm doing my first steps with the code and try to create a random animation, but always shows the last result and last position. Not displayed all intermediate positions. Why?

I've tried at various events and various browsers but no way.

var i = 0;

for (i=0; i<=1000; i++)

          {

          var x = Math.random() * 1000

          var y = Math.random() * 1000

          sym.$('rectangle').css('left', x).css('top', y);

          // Change an Element's contents.

          //  (sym.$("name") resolves an Edge Animate element name to a DOM

          //  element that can be used with jQuery)

          sym.$("text").html(i);

          sym.$("textx").html(x);

          sym.$("texty").html(y);

          }