var i
i = 0;
var anzahlBilder;
anzahlBilder = 23;

 function weiter_de()
{
if (i < anzahlBilder)
{
 i=++i;
 if (i != 1) document.anchors[1].style.visibility = "visible";
 document.typ.src = "../typen/de/de_" + i + ".gif";
 document.bild.src = "../ventile/" + i + ".gif";
 document.text.src = "../texte/de/de_" + i + ".gif";
 if (i == anzahlBilder) 
{
   document.anchors[0].style.visibility = "hidden";
   document.text.style.visibility = "hidden";
}

}
else
{
 alert("Ende");

}

 }

 function zurueck_de()
{

if (i != 1)
{
 if (i == anzahlBilder)
{
    document.anchors[0].style.visibility = "visible"; 
    document.text.style.visibility = "visible";
}

 i=--i;
 document.typ.src = "../typen/de/de_" + i + ".gif";
 document.bild.src = "../ventile/" + i + ".gif";
 document.text.src = "../texte/de/de_" + i + ".gif";
 if (i == 1) document.anchors[1].style.visibility = "hidden";
}
else
{
 alert("Ende");
}

 }


 function weiter_en()
{
if (i < anzahlBilder)
{
 i=++i;
 if (i != 1) document.anchors[1].style.visibility = "visible";
 document.typ.src = "../typen/en/en_" + i + ".gif";
 document.bild.src = "../ventile/" + i + ".gif";
 document.text.src = "../texte/en/en_" + i + ".gif";
 if (i == anzahlBilder)
{
   document.anchors[0].style.visibility = "hidden";
   document.text.style.visibility = "hidden";
}

}
else
{
 alert("Ende");

}

 }

 function zurueck_en()
{

if (i != 1)
{
 if (i == anzahlBilder)
{
    document.anchors[0].style.visibility = "visible"; 
    document.text.style.visibility = "visible";
}
 i=--i;
 document.typ.src = "../typen/en/en_" + i + ".gif";
 document.bild.src = "../ventile/" + i + ".gif";
 document.text.src = "../texte/en/en_" + i + ".gif";
 if (i == 1) document.anchors[1].style.visibility = "hidden";
}
else
{
 alert("Ende");
}

 }