function setRandomVensterStyle() {

    if(window.name!="")return; //style per session
    
    var menustyles = "";
    menustyles += getRandomMenuSting("kust") + ";";
    menustyles += getRandomMenuSting("rivier") + ";";
    menustyles += getRandomMenuSting("bodem") + ";";
    menustyles += getRandomMenuSting("beleid") + ";";
    window.name = menustyles;
    preloadImages();
}
  
function getRandomMenuSting(baseName) {
    return baseName + Math.floor(Math.random() * 3.999);
}

function getRandomVensterStyle()
{
    var className;
    $("#main_nav li").each(function (i) {
          className = getRandomVensterClass(i);
          if(className != null)
          {
              this.className = className;
          }
    });
}

function getRandomVensterClass(no)
{
    var arrClasses = window.name.split(";");
    if(no<arrClasses.length-1)
    {
        return arrClasses[no];
    }
    return null;
}

function preloadImages()
{
    var arrClasses = window.name.split(";");
    var img;
    var name;
    for(i=0;i<arrClasses.length;i++)
    {
        name = getRandomVensterClass(i);
        img = new Image();
        img.src = "/TXP/deltares-internet/images/" + name + "_page.jpg";
        img = new Image();
        img.src = "/TXP/deltares-internet/images/" + name + "_home.jpg";
        img = new Image();
        img.src = "/TXP/deltares-internet/images/" + name + "_hoofdvenster.jpg";
        
    }
}