How we can increase the width of the Page in nopCommerce ?

please guide me how i can increase the width of the page to make it little more wider, i dont want to wide it much but little more wide will be fine because currectly the width is very small for my requirements
if you wanna be more clear about that width i am talking about then please click on following link to see the screen shot:
http://img132.imageshack.us/img132/5554/sizex.jpg
Please guide me from where and how i can increase the width...

anyone ? please help

look in app_themes-->darkorange  master.css - you want to change the wrapper widths

i tried but its not changing anything, it's still the same thing
and how  4 categories could be displayed in a row on homepage after increasing the width of the page ?
By changing the width will change width of all the pages right ?

Please help me or show me here what exactly to change etc..Please help

there are several wrapper widths you have to change - start with master.css

.master-wrapper-page to begin with i guess then maybe
.master-wrapper-side
.master-wrapper-center etc etc

you may also want to change the widths of product grid etc

there may be many things to change - only you can decide what to change them to because only you know what you want. the best advice is to download the firefox browser and the firebug  tool for it - it lets you analyse the page and lets you see which css classes you will need to edit (it even tells you the .css file its and line number)

thanks for the detailed information, i installed firebug and it is a very good application
But the things is
i did change width of these following from 830px to 920px:
.master-wrapper-page
.master-wrapper-side
.master-wrapper-center

But whenever i try to run the project the changes cannot be seen i dont know why ? its still thr default width and nothing is changes, i tried debugging the whole project, cleared logs/catch , restarted my system, restarted Visual Studio but no change

Please help

thanks for the detailed information, i installed firebug and it is a very good application
But the things is
i did change width of these following from 830px to 920px:
.master-wrapper-page
.master-wrapper-side
.master-wrapper-center

But whenever i try to run the project the changes cannot be seen i dont know why ? its still thr default width and nothing is changes, i tried debugging the whole project, cleared logs/catch , restarted my system, restarted Visual Studio but no change

Please help