How set background image in header

[aliejus]

Is it possible to set background image in header, behind search box,logo and so on? in presta 1.4

[aliejus]

Help me someone please.

[Zion Zangar]

edit file:
http://shopname.com/themes/nametheme/css/global.css

image folder:
http://shopname.com/themes/nametheme/img/bigbg.jpg

body {
   background: #000000 url(../img/bigbg.jpg);
   background-repeat: norepeat top;
   background-attachment:fixed;
   font-size: 11px;
   font-family: Verdana, Arial, Helvetica, Sans-Serif;
   color: #5d717e;
   text-align:center;
}

Have a nice day

[armadillo]

Hi, i want to add a background just on authentication.tpl, i find authentication.css but which code i have to add for background image?