I'm making a website with DNN 6 and want it now an image on the top left in the background . I've tried a few things but the image is not visible on the site.

I've tried in the Style sheet Editor the next line:

#Body {
background-image: url(Portals/0/Images/background.png);
}

I’ve tried the same line also in the Skin css but there appears no picture on the site.

html{height:100%;}
#Body{height:100%;font-family:Helvetica, Arial, sans-serif;color:#333;}
#Body {
background-image: url(Portals/0/Images/background.png);
}
#Form{height:100%;}
a{outline:0;border:0;}
p, ul, ol{margin:0;padding:0 0 1em 0;}
#DNN6{width:100%;position:relative;z-index:1;min-height:100%;background-color:#fafafa;}
#Background{background:#fafafa url('Images/Body-BG.jpg') repeat-x 0 bottom;position:absolute;bottom:0;width:100%;height:240px;z-index:-1;}

What am I doing wrong.

It worked with this tutorial

Changing the background image of a Dotnetnuke Website  

Thanks anyway