Extra Forum WIDTH & Scrollbar problem

[sual1234567890]

Hello Sir, its a pleasure meeting the top staffs of PC! I have a problem with my forum i created for personal use, i thought you guys know about technology, can you tell me what is wrong here and HOW can i fix it? this extra width on the right side appears only when i enter into thread and not for all forums! Also the horizontal scrollbar appears only when there is extra width on the right side, and not on the homepage etc! Waiting forward for your kind reply. heres the photo :

 

[asprin]

Just a photo won't do any help. You'll also need to show the related CSS. One thing you can try is using

width:100%

on the div/siblings and see if that solves it.