function hidediv(divname) {
	document.getElementById(divname).style.visibility = 'hidden';
}

function showdiv(divname) {
	document.getElementById(divname).style.visibility = 'visible';
}

function hideall() {
	document.getElementById('div1').style.visibility = 'hidden';
	document.getElementById('div2').style.visibility = 'hidden';
	document.getElementById('div3').style.visibility = 'hidden';
	document.getElementById('div4').style.visibility = 'hidden';
	document.getElementById('div5').style.visibility = 'hidden';
	document.getElementById('div6').style.visibility = 'hidden';
	document.getElementById('div7').style.visibility = 'hidden';
	document.getElementById('div8').style.visibility = 'hidden';
	document.getElementById('div9').style.visibility = 'hidden';
	document.getElementById('div10').style.visibility = 'hidden';
	document.getElementById('div11').style.visibility = 'hidden';
}