Drag, Drop, Lock! How to lock it!

Hi ppl! i am doing a simple math quiz. For one of the question, i would like the user to drag and drop an image to a specific area where it will auto lock it. Just like this example. How do i do it on titanium for ios?

This is the code i am currently making use of for drag and drop:

var win = Ti.UI.currentWindow;
 
var imageView = Titanium.UI.createImageView({
    image:'http://www.appcelerator.com/wp-content/uploads/2009/06/titanium_desk.png',
    width:261,
    height:178,
    top:20
}),
olt = Titanium.UI.create3DMatrix(),
    curX, curY;
 
imageView.addEventListener('touchstart',function(e){ 
    curX = e.x;
    curY = e.y;
});
imageView.addEventListener('touchmove',function(e){ 
    var deltaX = e.x - curX,
        deltaY = e.y -curY;
    olt = olt.translate(deltaX,deltaY,0);
    imageView.animate({transform: olt, duration: 100}); 
});
win.add(imageView);