function changeStand(index) {
    if (index==2) {
	document.getElementById('ss').style.display = 'block'; 
	document.getElementById('sp').style.display = 'none'; 
    } else if (index==3) {
	document.getElementById('ss').style.display = 'none'; 
	document.getElementById('sp').style.display = 'block';
    }
}

function calc() {
    var discount1 = document.getElementById('data1').checked ? 0.1 : 0;
    var discount2 = document.getElementById('m1').checked ? 0.1 : 0;
    if (document.getElementById('tip_stand').value==2) {
	var ms = document.getElementById('ms2').checked ? 2 : (document.getElementById('ms3').checked ? 3 : 1);
	document.getElementById('pret_total').value = Math.round(390 * ms * (1 - discount1) * (1 - discount2) * 100) / 100;
    } else if (document.getElementById('tip_stand').value==3) {
	document.getElementById('pret_total').value = Math.round(50 * parseFloat(document.getElementById('suprafata').value) * (1 - discount1) * (1 - discount2) * 100) / 100;
    } else {
	alert('Alegeti tipul de stand dorit !');
    }
}