function setDisplaySwitch(source_o)
{
	//var element_o = document.getElementById(source_o);

	var element_o = document.getElementById(source_o);

		if(element_o.style.display == 'none')
		{
			element_o.style.display = '';
		}
		else
		{
			element_o.style.display = 'none';
		}
};

function closeAll()
{
	element_a = new Array('zuidholland','groningen','noordholland','flevoland');

	for(i = 0; i < element_a.length; i++)
	{
		element_o = document.getElementById(element_a[i]);
		element_o.style.display = 'none'
	}
};