function showBranch(branch) {
	var objBranch = document.getElementById("_" + branch).style;
	if(objBranch.display == "block") {
		objBranch.display = "none";
		document.getElementById(branch).innerHTML = "+";
	}
	else {
		objBranch.display = "block";
		document.getElementById(branch).innerHTML = "-";
	}
}