MyBB Community Forums

look at this site, their banner is matched with background (you can check by scrolling down).
I want use their style in my theme
at first I created an static background

  background: #FFFFFF url(/images/14516313225907281785.jpg);
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-position-x: 50%;
  background-position-y: -1%;
  background-origin: initial;
  background-clip: initial;
  color: #000;
  text-align: center;
  line-height: 1.4;
  margin: 0px;

and then used a transparent png image to determining part of background that should be used in banner.
I used snipping tool to crop a section of background that equals with banner.
after inserting banner, I found that banner hadn't mach background
I'd set body using position:absolute command to mach

position:absolute;
  left:14.15%;
  top:0.755%;

it works in my display, but no success in other resolutions, please help me
see attachment for more details
[attachment=25747]

Not a MyBB related issue im affraid.

this is mybb support forums,NOT VBULLETIN,Sorry.

I have mybb!
just wanted having similar background & logo set

Ok. It would help us a great deal if you could post a link to your forum.
And by looking at you attachment it looks like the border at the top of your banner is making your background look stepped. This can be quite easily fixed but will require a few image snips in photoshop and a few CSS modificaitons.