Advanced scripting! HELP!

Hi all!
I have two questions, both of which i don even know if are possible, but it never hurts to ask :beam:

Any way, first, is it possible to change the alpha of a movie clip dependant on a colour. In my case, i want to creat a sneaking game, eg “Metal Gear Solid”, ive created my level and everything, with shadows, but all as 1 image using a 3dS Max, what i want to happen is, when my main character is ontop of a dark area, a shadow, his alpha will change dependant on how dark that area is.
Again, i wont be suprised if it isnt even possible, but it would make my life a hell of a lot easier.

Ok, my next question is a little more down to earth (I think :wink: ). I am using this script:

adjside = _root._xmouse-this._x;
oppside = -1*(_root._ymouse-this._y);
angle = Math.atan2(oppside, adjside);
angle = Math.round(angle/Math.PI*180);
this.turret._rotation = 270-angle-this._rotation;

to rotate a movie clip, inside a move clip, towards the direction of the mouse. However it isn’t really what i need. What happens with this code is the movie clip constantly faces the mouse, but what i want is for the movie clip to gradually rotate towards the direction of the mouse,

e.g, this._rotation+=5.

Ive played around with this and found no solution, but theres got to be one :ogre: .

I hope u reply, id be really greatful.
Thanks for the time.