new_window = null;

function start_window()
{
	new_window = open ("http://www.at2-group.com/formular/formular.html", "katalog_down", "status = no, height = 300, width = 350, resizable = no, toolbar = no, menubar = no, titlebar = no");

}

function check(aa, bb, cc)
{
var aaa = aa.value;
var bbb = bb.value.length;
var ccc = cc.value.length;

if (aaa == 0 ||bbb == 0 ||ccc == 0)
{
alert("Sie mussen alle Felder ausfüllen!");
}
}