var bV=parseInt(navigator.appVersion);
NS4=(document.layers) ? true : false;
IE4=((document.all)&&(bV>=4))?true:false;
ver4 = (NS4 || IE4) ? true : false;

    if (ver4) {
      firstIm = "<img src='images/anfahrt.jpg' usemap='#mpMenu' width=729 height=579 border=0>";
     secondIm = "<img src='images/onmit.jpg' usemap='#mpMenu' width=729 height=579 border=0>";
    }
    else {
      firstIm = "<IMG SRC='images/anfahrt.jpg' usemap='#mpMenu' width=729 height=579 border=0>";
     secondIm = "";
    }