Is there a way to keep dropdown's mouse over state stay on to test css styling in firefox?

Is there a way to keep dropdown's stay on to test css styling in firefox?

for example : suppose if on this page http://www.htmldog.com/articles/suckerfish/dropdowns/example/bones1.html i want to keep dropdown on just to edit 开发者_StackOverflow中文版and styles in firebug.

Edit: the given link is just an example

Alter the CSS styles so it displays the secondary ul without needing a :hover. Alternatively toggle classnames through JS console to do the same thing.

remove the css:

#nav li ul {
    left:-999em;
}

On firebug, select the link above the <ul>. You'll see the <ul> even though it's hidden. Select it, and disable the left:-999em; rule:

alt text http://img401.imageshack.us/img401/7822/firebugdetails.png

Search for left: -999em; and change it to left: auto;. PS: Ln 35