How to create an editing panel

See more:

C#

HTML

WPF

data-binding

Hello ,
i am creating a HTML page offline creator all what you have to do is to drag an object to your page to implement it but i am facing a problem in the drag and drop , how to get the location of an object after it is dragged for example if we have a button tool in the tool box that enable you to add a button to your html page then you dragged it and dropped it in (112,112)
pixels from the start of the screen hoe to get it's location from the panel and how to drop it in it's position