function showNavOptions(optionName){
	
	document.getElementById('row1_1').style.visibility = "hidden";
	document.getElementById('row1_2').style.visibility = "hidden";
	document.getElementById('row1_3').style.visibility = "hidden";
	document.getElementById('row1_4').style.visibility = "hidden";

	document.getElementById('row2_1').style.visibility = "hidden";
	document.getElementById('row2_2').style.visibility = "hidden";
	document.getElementById('row2_3').style.visibility = "hidden";
	document.getElementById('row2_4').style.visibility = "hidden";

	document.getElementById('row3_1').style.visibility = "hidden";
	document.getElementById('row3_2').style.visibility = "hidden";
	document.getElementById('row3_3').style.visibility = "hidden";
	document.getElementById('row3_4').style.visibility = "hidden";

	document.getElementById('row4_1').style.visibility = "hidden";
	document.getElementById('row4_2').style.visibility = "hidden";
	document.getElementById('row4_3').style.visibility = "hidden";
	document.getElementById('row4_4').style.visibility = "hidden";

	document.getElementById('row5_1').style.visibility = "hidden";
	document.getElementById('row5_2').style.visibility = "hidden";
	document.getElementById('row5_3').style.visibility = "hidden";
	document.getElementById('row5_4').style.visibility = "hidden";

	if(optionName=='home')
	{
		document.getElementById('sub1').style.visibility = "visible";
		document.getElementById('sub2').style.visibility = "visible";
		document.getElementById('sub3').style.visibility = "visible";
		document.getElementById('sub4').style.visibility = "hidden";
		document.getElementById('sub5').style.visibility = "hidden";

		document.getElementById('row1_1').style.visibility = "visible";
		document.getElementById('row2_1').style.visibility = "visible";
		document.getElementById('row3_1').style.visibility = "visible";
		document.getElementById('row4_1').style.visibility = "visible";
		document.getElementById('row5_1').style.visibility = "visible";
	}

	if(optionName=='tuin')
	{
		document.getElementById('sub1').style.visibility = "visible";
		document.getElementById('sub2').style.visibility = "visible";
		document.getElementById('sub3').style.visibility = "visible";
		document.getElementById('sub4').style.visibility = "hidden";
		document.getElementById('sub5').style.visibility = "hidden";

		document.getElementById('row1_2').style.visibility = "visible";
		document.getElementById('row2_2').style.visibility = "visible";
		document.getElementById('row3_2').style.visibility = "visible";
	}

	if(optionName=='vijver')
	{
		document.getElementById('sub1').style.visibility = "visible";
		document.getElementById('sub2').style.visibility = "visible";
		document.getElementById('sub3').style.visibility = "visible";
		document.getElementById('sub4').style.visibility = "hidden";
		document.getElementById('sub5').style.visibility = "hidden";

		document.getElementById('row1_3').style.visibility = "visible";
		document.getElementById('row2_3').style.visibility = "visible";
		document.getElementById('row3_3').style.visibility = "visible";
	}

	if(optionName=='dak')
	{
		document.getElementById('sub1').style.visibility = "hidden";
		document.getElementById('sub2').style.visibility = "hidden";
		document.getElementById('sub3').style.visibility = "hidden";
		document.getElementById('sub4').style.visibility = "hidden";
		document.getElementById('sub5').style.visibility = "hidden";

		document.getElementById('row1_4').style.visibility = "visible";
	}}

if (document.images) {
	nav_home = new Image();
	nav_home.src = "img/home.gif";
	nav_homeover = new Image();
	nav_homeover.src = "img/home_over.gif";
	
	nav_tuin = new Image();
	nav_tuin.src = "img/tuinen.gif";
	nav_tuinover = new Image();
	nav_tuinover.src = "img/tuinen_over.gif";
	
	nav_vijver = new Image();
	nav_vijver.src = "img/vijver.gif";
	nav_vijverover = new Image();
	nav_vijverover.src = "img/vijver_over.gif";
	
	nav_dak = new Image();
	nav_dak.src = "img/dakbeplanting.gif";
	nav_dakover = new Image();
	nav_dakover.src = "img/dakbeplanting_over.gif";

	nav_pro = new Image();
	nav_pro.src = "img/projecten.gif";
	nav_proover = new Image();
	nav_proover.src = "img/projecten_over.gif";

	nav_contact = new Image();
	nav_contact.src = "img/bottom_btn.gif";
	nav_contactover = new Image();
	nav_contactover.src = "img/bottom_btn.gif";
}
	
	
function swapOn(imgName) {
	if (document.images) {
	eval("document." + imgName + ".src = " + imgName + "over.src");
	}
}

function swapOff(imgName) {
	if (document.images) {
	eval("document." + imgName + ".src = " + imgName + ".src");
	}
}

function selectRowOn(id) {
	document.getElementById(id).style.fontColor="#ff0000";
	}

function selectRowOff(id) {
	document.getElementById(id).style.fontColor="#ffffff";
}
function go(field)
{
	parent.main.location.href="main.php?field="+field;
}