previousStep = "step00";
previousPlan = "plan01";

function toggleStep(id) {
	hideDocumentElement(previousStep);
	document.getElementById('step00').style.display="none";
	showDocumentElement(id);
	previousStep = id;
}

function togglePlan(id) {
	hideDocumentElement(previousPlan);
	document.getElementById('plan01').style.display="none";
	showDocumentElement(id);
	previousPlan = id;
}

function hideDocumentElement(id) {
    var el = document.getElementById(id);
    if (el) el.style.display = 'none';
}

function showDocumentElement(id) {
    var el = document.getElementById(id);
    if (el) el.style.display = 'block';
}