function CheckAll(node)
{
	var elem;
	var i= 0;
	var name= node +i;
	
	while(elem=document.getElementById(name))
	{
		if (document.getElementById(name).checked == true)
			document.getElementById(name).checked= false;
		else
			document.getElementById(name).checked= true;
		i++;
		name= node + i;
	}	
}

function checkNumeric(node)
{	
	var i= 0;
	while (i < node.value.length)
	{
		if ((node.value.charAt(i) < '0') || (node.value.charAt(i) > '9'))
			return -1;		
		i++;
	}
	node.className = 'inp1';
	return 0;
}

function checkNumericAll()
{
	var i;
	var k = 0;
	var ret = true;
	var elem;
	var name= 'number' + k;
	while(elem=document.getElementById(name))
	{
		if (checkNumeric(elem) == -1)
		{
			ret = false;	
			document.getElementById('number_error' + k).style.display = 'block';
		}
		else
			document.getElementById('number_error' + k).style.display = 'none';
		k++;
		name= 'number' + k;
	}	
	
	// Items to unlink
	k = 0;
	name= 'del' + k;
	var node = document.getElementById('pages_to_unlink');
	node.value = '';
	while(elem=document.getElementById(name))
	{
		if (elem.checked == false)
		{
			if (node.value == '')
				node.value = elem.value;
			else
				node.value = node.value + ',' + elem.value;
		}
		k++;
		name= 'del' + k;
	}
	return ret;
}

function enableFields(node)
{
	if (node.selectedIndex == 0)
	{
		document.getElementById('page_nr').disabled = true;
		document.getElementById('cover0').disabled = true;
		document.getElementById('cover1').disabled = true;
	}
	else
	{
		document.getElementById('page_nr').disabled = false;
		document.getElementById('cover0').disabled = false;
		document.getElementById('cover1').disabled = false;
	}
}

function enableNr(node)
{
	if (node.value == 1)
		document.getElementById('page_nr').disabled = true;
	else
		document.getElementById('page_nr').disabled = false;
}