function my_stateButton(   canvasName )

{

    this.canvas = document.getElementById(canvasName);

​

    this.canvas.onmousedown = function() {

       alert('down');

    };

    this.canvas.onmouseup = function() {

        alert('up');  

    };

​

   console.log('constructing statebutton for id '+canvasName);

​

    // Do some work

}

​

var btn1 = new my_stateButton( "Area-Light");