As you can see, you need to know the htmlname of your element.
The cross is image40
And you need to add variables for the x and y position of your element... Like here...
If you now move/change the position of the Cross by clicking on it... then click the button Show X/Y Position... the postion is shown in the textfield.
Only Javascript needed is on the button
The cross is now at x-position 34 and y-position 447