function impressum() {
  f1 = window.open("impressum.html","impressum","width=560,height=610,left=0,top=0");
}

function schule() {
  f2 = window.open("schule.html","schule","width=450,height=300,left=0,top=0");
}

function anfahrt1() {
  f3 = window.open("anfahrt1.html","anfahrt","width=744,height=706,left=0,top=0");
}
function anfahrt2() {
  f4 = window.open("anfahrt2.html","anfahrt","width=450,height=369,left=0,top=0");
}

function kollegium() {
  f5 = window.open("kollegium2.html","kollegium","width=500,height=300,left=0,top=0");
}

function ro(bildname,nr) {
  if (document.images) {
    switch(nr) {
      case "1":
        document[bildname].src = b1_ro.src;
        break;
      case "2":
        document[bildname].src = b2_ro.src;
        break;
      case "3":
        document[bildname].src = b3_ro.src;
        break;
      default:
        break;
    }
  }
}

function st(bildname) {
  if (document.images) {
    document[bildname].src = b_st.src;
  }
}

b1_ro = new Image();
b1_ro.src = "bilder/pfeil1.gif";
b2_ro = new Image();
b2_ro.src = "bilder/pfeil2.gif";
b3_ro = new Image();
b3_ro.src = "bilder/pfeil3.gif";
b_st = new Image();
b_st.src = "bilder/pixel.gif";