exibe = function(div) {
	document.getElementById("co1").style.display = "none";
	document.getElementById("co2").style.display = "none";
	document.getElementById("co3").style.display = "none";
	document.getElementById("co4").style.display = "none";
	document.getElementById("co5").style.display = "none";
	document.getElementById("co6").style.display = "none";
	
	document.getElementById(div).style.display = "block";
}