function loadSilhouet(){
    document.getElementById("leftnav").style.backgroundImage=images[Math.floor(Math.random()*4)];
}

var path=document.location.href;
path=path.substring(0,path.lastIndexOf('/'));


var images=new Array();
var preLoad=new Array();
for(var i=0;i<4;i++){
    images[i]="url('" + path + "/images/silhouttes/silhouettes_00" + (i+1) + ".jpg')";
    preLoad[i]=new Image();
    preLoad[i].src=images[i];
}