Save keyboard.html as attributes.html.  Paste this code under the last p but inside the the body:

<div  onmousedown="clickPos(event)" style="height:300px; width:400px; background-color:blue;">            
    <p>Click anywhere in this DIV</p>            
</div>

That just creates a new div to click on.  Now put the function inside the script element near the top of your code:

function clickPos(e){
    var positionx=e.screenX;
    var positiony=e.screenY;
    alert('Mouse position was '+positionx+':'+positiony);
} 

Now you can click anywhere in the new div and be told the position of the click.  To explain:

  1. the event trigger (in the div) is sending a parameter, you did not create a variable called event because it is a special one which holds details about the event
  2. the parameter is received by the function and stored into a new variable (actually an object) called e (it could be called anything)
  3. the e object has a lot of information (properties) but we just get out the mouse position and store it in variables
  4. the position is reported

You could do something at that position rather than just report it.  Note that the position was the position on the screen (pixels from the left and from the top).  If you have dual monitors it treats them as one.  You can also report or use other details as you will find out soon.