function changeCheckboxState(name, onOrOff)
{
	var i = 0;
	var checkbox = null;

	while ( checkbox = document.getElementById(name + "_" + i) ) {
		checkbox.checked = onOrOff;	
		i++;
	}
}

function toggleBlock(blockId)
{
	var blockElement = document.getElementById(blockId);
	if ( blockElement.style.display == 'none' ) {
		blockElement.style.display = 'block';
	} else {
		blockElement.style.display = 'none';
	}
}