I try to add some div(s) to the sides of the main div for that I have #maindiv ( position:relative) #borderright ( position: absolute; background: red; width: 3px; height: 100%; right: 0) #borderleft( position: absolute; background: red; width: 3px; height: 100%; left:0) now when I do <div id="maindiv"> <div id="borderright"> </div> <div id="rightborder"> </div> <div id="leftborder"> </div> </div> Their is only 1 div showing ( the left one) if I delete the left div the right one is showing... What am I doing wrong ? Thanks for your help Edit: When I look to the css with Chrome, it seems that div id rightborder style is empty, and if I had the styles myself in view mode it works !? Again, if I delet the left di (leftborder) the rightborder is showing up... Weird isn't it ? edit2: maindiv has dimentions, don't pay atention to the fact that div are diferentmy names in the css and in the html.