Div's centreren

Goedendag,

Ik probeer mijn site in het midden van de pagina te krijgen maar het wil niet echt lukken
hij moet alleen horizontaal gecentreerd worden
in layer 34 zitten alle andere layers
voorbeeld: http://84.83.30.85/SkullDump

dit is de css die ik gebruik voor mijn site:

body {
border: 0;
padding: 0;
text-align: center;
height: 96%;
}

#Layer34 {
width: 955px;
height: 500px;
margin-left: auto;
margin-right: auto;
margin-top: 9%;
}



#Layer1 {
    position:absolute;
    left:0px;
    top:0px;
    width:180px;
    height:77px;
    z-index:8;
    background-image: url(Afbeeldingen/Grid 3.gif);
    background-image: url(Afbeeldingen/Grid%204.png);
}
#Layer2 {
    position:absolute;
    left:180px;
    top:0px;
    width:626px;
    height:77px;
    z-index:9;
    background-color: #191919;
}
#Layer3 {
    position:absolute;
    left:806px;
    top:0px;
    width:190px;
    height:77px;
    z-index:10;
    background-image: url(Afbeeldingen/Grid%201.PNG);
}
body {
    background-color: #191919;
}
#Layer4 {
    position:absolute;
    left:0px;
    top:77px;
    width:996px;
    height:25px;
    z-index:11;
    background-image: url(Afbeeldingen/Balk%201.PNG);
}
#Layer5 {
    position:absolute;
    left:0px;
    top:102px;
    width:180px;
    height:350px;
    z-index:12;
    background-image: url(Afbeeldingen/Grid%202.PNG);
}
#Layer6 {
    position:absolute;
    left:180px;
    top:102px;
    width:816px;
    height:350px;
    z-index:13;
    background-color: #354147;
}
#Layer7 {
    position:absolute;
    left:0px;
    top:450px;
    width:996px;
    height:25px;
    z-index:14;
    background-image: url(Afbeeldingen/Balk%201.PNG);
}
#Layer8 {
    position:absolute;
    left:0px;
    top:477px;
    width:180px;
    height:133px;
    z-index:15;
    background-image: url(Afbeeldingen/Grid%203.gif);
}
#Layer9 {
    position:absolute;
    left:25px;
    top:118px;
    width:98px;
    height:27px;
    z-index:9;
}
#Layer10 {
    position:absolute;
    left:25px;
    top:310px;
    width:98px;
    height:27px;
    z-index:10;
}
#Layer11 {
    position:absolute;
    left:25px;
    top:246px;
    width:98px;
    height:27px;
    z-index:11;
}
#Layer12 {
    position:absolute;
    left:25px;
    top:182px;
    width:98px;
    height:27px;
    z-index:12;
}
#Layer13 {
    position:absolute;
    left:25px;
    top:214px;
    width:98px;
    height:27px;
    z-index:13;
}
#Layer14 {
    position:absolute;
    left:25px;
    top:278px;
    width:98px;
    height:27px;
    z-index:14;
}
#Layer15 {
    position:absolute;
    left:25px;
    top:150px;
    width:98px;
    height:27px;
    z-index:15;
}
#Layer16 {
    position:absolute;
    left:937px;
    top:78px;
    width:62px;
    height:25px;
    z-index:16;
}
#Layer17 {
    position:absolute;
    left:2px;
    top:576px;
    width:136px;
    height:25px;
    z-index:17;
}
#Layer18 {
    position:absolute;
    left:2px;
    top:568px;
    width:64px;
    height:43px;
    z-index:18;
    background-color: #FFFFFF;
}
#Layer19 {
    position:absolute;
    left:176px;
    top:0px;
    width:225px;
    height:78;
    z-index:19;
}
#Layer20 {
    position:absolute;
    left:363px;
    top:511px;
    width:83px;
    height:57px;
    z-index:19;
}
#Layer21 {
    position:absolute;
    left:194px;
    top:121px;
    width:703px;
    height:25px;
    z-index:18;
    background-color: #191919;
}
#Layer22 {
    position:absolute;
    left:183px;
    top:596px;
    width:321px;
    height:13px;
    z-index:19;
}
#Layer23 {
    position:absolute;
    left:264px;
    top:270px;
    width:78px;
    height:39px;
    z-index:20;
}
#Layer24 {
    position:absolute;
    left:279px;
    top:207px;
    width:59px;
    height:33px;
    z-index:20;
}
#Layer25 {
    position:absolute;
    left:39px;
    top:0px;
    width:66px;
    height:40px;
    z-index:20;
}
#Layer26 {
    position:absolute;
    left:25px;
    top:134px;
    width:98px;
    height:27px;
    z-index:20;
}
#Layer27 {
    position:absolute;
    left:25px;
    top:171px;
    width:98px;
    height:27px;
    z-index:21;
}
#Layer28 {
    position:absolute;
    left:25px;
    top:207px;
    width:98px;
    height:27px;
    z-index:22;
}
#Layer29 {
    position:absolute;
    left:25px;
    top:243px;
    width:98px;
    height:27px;
    z-index:23;
}
#Layer30 {
    position:absolute;
    left:25px;
    top:279px;
    width:98px;
    height:27px;
    z-index:24;
}
#Layer31 {
    position:absolute;
    left:25px;
    top:315px;
    width:98px;
    height:27px;
    z-index:25;
}
#Layer32 {
    position:absolute;
    left:25px;
    top:387px;
    width:98px;
    height:27px;
    z-index:26;
}
#Layer33 {
    position:absolute;
    left:25px;
    top:351px;
    width:98px;
    height:25px;
    z-index:27;
}

Iemand enig idee hoe ik dit kan oplossen?
Dat ik als ik een resolutie heb van 1280x786 de site netjes horizontaal is gecentreerd op het beeldscherm?