Create opaque effect on window panes using photoshop

Hi, i need a freelancer to create 6 x different levels of opacity based on the attached picture. The windows shown in the picture is clear where you can see through the trees outside, but I want 6 different effects where the windows slowly turn opaque, and finally into white. For reference, please go to [login to view URL], go to the picture on the right, move the slider and see how it changes the opacity of the picture. Please only bid if you have experience doing this. If you bid and win, then come asking me what this is about or even how to do it, I'm going to leave very very bad feedback on your page. Thanks.