function showColumn1()
{
	showElement("dropdown1");
	hideElement("dropdown2");
	hideElement("dropdown3");
	hideElement("dropdown4");
}

function showColumn2()
{
	hideElement("dropdown1");
	showElement("dropdown2");
	hideElement("dropdown3");
	hideElement("dropdown4");

}

function showColumn3()
{
	hideElement("dropdown1");
	hideElement("dropdown2");
	showElement("dropdown3");
	hideElement("dropdown4");
}

function showColumn4()
{
	hideElement("dropdown1");
	hideElement("dropdown2");
	hideElement("dropdown3");
	showElement("dropdown4");
}

function showHead()
{
}

function hideElement(name)
{
	document.getElementById(name).style.display = "none";
}

function showElement(name)
{
	var el = document.getElementById(name);
	if (el.style.display == "block")
	{
		el.style.display = "none";		
	}
	else
	{
		el.style.display = "block";
	}
}