var N   = (document.layers) ? true:false;                 // netscape 4
var IE   = (document.all) ? true:false;                    // ie4+
var DOM = ((document.getElementById)&&(!IE))?true:false;   // ns6 etc.


function NewData() {
var celkem = 2500;    

if (document.form.dokt.checked) celkem = celkem - 1000;
if (document.form.Accommoda1.checked) celkem = celkem + 720;
if (document.form.Accommoda2.checked) celkem = celkem + 720;
if (document.form.Accommoda3.checked) celkem = celkem + 720;
if (document.form.Lunch2.checked) celkem = celkem + 130;
if (document.form.Lunch3.checked) celkem = celkem + 130;
if (document.form.Lunch4.checked) celkem = celkem + 130;
if (document.form.Dinner2.checked) celkem = celkem + 130;
if (document.form.Dinner3.checked) celkem = celkem + 130;

document.getElementById("platba").innerHTML=celkem;  
}