function setVisiblePanel(newPanelIndex) {
	var displayPanelIndexField = document.getElementById("displayPanelIndex");
	var oldPanelIndex = displayPanelIndexField.value;

	var newPanelId = "panel_" + newPanelIndex;
	var oldPanelId = "panel_" + oldPanelIndex;

	var newTabId = "tab_" + newPanelIndex;
	var oldTabId = "tab_" + oldPanelIndex;

	//alert("oldPanelIndex: " + oldPanelIndex + ", newPanelIndex: " + newPanelIndex + ".");

	var newPanel = document.getElementById(newPanelId);
	var oldPanel = document.getElementById(oldPanelId);

	var newTab = document.getElementById(newTabId);
	var oldTab = document.getElementById(oldTabId);

	//var currentPanelField = document.getElementById("displayPanel");
	//var currentPanelId = currentPanelField.value;
	//var currentPanel = document.getElementById(currentPanelId);

	oldPanel.style.display = "none";
	newPanel.style.display = "block";

	oldTab.className = "";
	newTab.className = "active";

	displayPanelIndexField.value = newPanelIndex;
}