//Bildwechsel-Funktion, name entspricht dem Namen des Bildes, bild dem Inhalt
function image_swap (name, bild){
  //kein bild und aktive Seite
  if (bild!=""){
     document.images[name].src = img_array[bild].src;
  }else{
     document.images[name].src = img_array[0].src;
  }
}

function preLoadImages(){
    img_array = new Array();
    img_array[0] = new Image();
    img_array[0].src = "images/home_a.gif";
    img_array[1] = new Image();
    img_array[1].src = "images/home_b.gif";
    img_array[2] = new Image();
    img_array[2].src = "images/home_c.gif";
    img_array[3] = new Image();
    img_array[3].src = "images/wir_sind_a.gif";
    img_array[4] = new Image();
    img_array[4].src = "images/wir_sind_b.gif";
    img_array[5] = new Image();
    img_array[5].src = "images/wir_sind_c.gif";
    img_array[6] = new Image();
    img_array[6].src = "images/leistungen_a.gif";
    img_array[7] = new Image();
    img_array[7].src = "images/leistungen_b.gif";
    img_array[8] = new Image();
    img_array[8].src = "images/leistungen_c.gif";
    img_array[9] = new Image();
    img_array[9].src = "images/gutachten_a.gif";
    img_array[10] = new Image();
    img_array[10].src = "images/gutachten_b.gif";
    img_array[11] = new Image();
    img_array[11].src = "images/gutachten_c.gif";
    img_array[12] = new Image();
    img_array[12].src = "images/checkliste_a.gif";
    img_array[13] = new Image();
    img_array[13].src = "images/checkliste_b.gif";
    img_array[14] = new Image();
    img_array[14].src = "images/checkliste_c.gif";
    img_array[15] = new Image();
    img_array[15].src = "images/kontakt_a.gif";
    img_array[16] = new Image();
    img_array[16].src = "images/kontakt_b.gif";
    img_array[17] = new Image();
    img_array[17].src = "images/kontakt_c.gif";
    img_array[18] = new Image();
    img_array[18].src = "images/arrow_inactive_right.gif";
    img_array[19] = new Image();
    img_array[19].src = "images/arrow_active_right.gif";
}