function personen ()
{
if(isNaN(parseInt(document.getElementById('typ1_num_1').value)))
{
document.getElementById('typ1_num_1').value = 0;
}
if(isNaN(parseInt(document.getElementById('typ1_num_2').value)))
{
document.getElementById('typ1_num_2').value = 0;
}
if(isNaN(parseInt(document.getElementById('typ1_num_3').value)))
{
document.getElementById('typ1_num_3').value = 0;
}
var personen_1 = parseInt(document.getElementById('typ1_num_1').value);
var personen_2 = parseInt(document.getElementById('typ1_num_2').value) * 2;
var personen_3 = parseInt(document.getElementById('typ1_num_3').value) * 3;
var personen_g = (personen_1 + personen_2 + personen_3);
document.getElementById('c_personen').value = personen_g;
}

var stadtplan;
function map (stadtplan)
{
fenster=window.open (stadtplan,"3","width=508,height=562,scrollbars=no,screenX=0,screenY=0");
}