How can I make a window wider?

[bs6600]

I provide html code which is 'plugged into a web site over which I have no control.

It shows the results of my code in a "window" or "box" which is centered on the screen and too narrow for my needs.

You can see my problem here

(Styling :width=130% is giving me a wider right margin - click to open to see that - crude I know.)

But is there any more elegant way I can change my code to give me a wider window?

Bill Spence,
Dunfermline, Scotland

 

[xwb]

Your link seems to have disappeared. Can't you just paste the image instead of a link?