visual controls

Question

I am using web browser control. I just want to show all spaces with red mark on my browser. so I can remove unnecessary spaces.


I want to do this with css.. because I don't want any changes in my html. 


I want to use it on a button. like when i press the button all spaces visible with red mark. and when I again click on that button all red mark invisible. In short I just want to make this button toggle.


Please give me the solution.