if (document.layers)  {
     ns = 1; ie = 0; 
} else {
     ns = 0; ie = 1;
     }
	 

var i = 1;
var test = "main";
function zeigeEbeneNr(ebene_nr){
    verbergen(eval('"' + test + i +'"'));
    zeigen(eval('"' + test + ebene_nr +'"'));
    i = ebene_nr; 
    }

function zeigen(name) {
if (ns) {
    document.layers[''+name].visibility = "show";		
    }
    else {
    document.all[''+name].style.visibility = "visible"
    }
}

function verbergen(name) {
if (ns){
    document.layers[''+name].visibility = "hide"
    }
    else {
    document.all[''+name].style.visibility = "hidden"
    }
}