function trim(s)
{
  while (s.substring(0,1) == ' ') {
    s = s.substring(1,s.length);
  }
  while (s.substring(s.length-1,s.length) == ' ') {
    s = s.substring(0,s.length-1);
  }
  return s;
}

function disableQuantity(id)
{
	select = document.getElementById('quantity_'+id);
	checkbox = document.getElementById('check_'+id);
	if (checkbox.checked)
		select.disabled = false;
	else
		select.disabled = true;
}

function disableAllSelects()
{
	for (var i=1; i<=6; i++)
	{
		disableQuantity(i);
	}
}

function enableShipping(enable)
{
	document.getElementById('s1').disabled = enable;
	document.getElementById('s2').disabled = enable;
	document.getElementById('s3').disabled = enable;
	document.getElementById('s5').disabled = enable;
	document.getElementById('s6').disabled = enable;
	document.getElementById('s7').disabled = enable;
	document.getElementById('s8').disabled = enable;
	document.getElementById('s9').disabled = enable;
	document.getElementById('s10').disabled = enable;
}

function checkSelected()
{
	var selected = false;
	var selects = document.getElementsByName('sel_pr[]');
	for (i=0; i<6; i++)
	{
		if(selects[i].checked)
			selected = true;
			
	}
	
	if (!selected)
		alert('Please select at least one product!');
	return selected;
}