--ok first thing to do is make a new document any size then color the backround any color (i choose white)
then put your text in.
http://i1.tinypic.com/nl1p39.jpg
--now go layer>new then name it Gradient now take the gradient tool and make a mark like so
http://i1.tinypic.com/nl1rh0.jpg
--Now press Ctrl+I then set the blend mode to lighten
--then press this button
http://i1.tinypic.com/nl1se8.jpg
--Now when you in imageready go to the top and press Window>Animation
--Now press the little button in the top right corner and select new frame
http://i1.tinypic.com/nl1ugl.jpg
--now take your gradient layer and press Shift and Drag the gradient layer from where it was to where you want it to go.
--then click the tween button and use these settings
http://i1.tinypic.com/nl1vsg.jpg
--Now your thing should turn out like this
http://i1.tinypic.com/nl1xjt.gif