function expandContent() {
	var leftPanel = document.getElementById("vtLeftPanel");
	var contentPanel = document.getElementById("vtContentPanel");
	var rightPanel = document.getElementById("vtRightPanel");
	var btnPicture = document.getElementById("vtButtonExpandReducePicture");
	var btnText = document.getElementById("vtButtonExpandReduceText");
	
	leftPanel.style.display= "none";
	rightPanel.style.display= "none";
	btnPicture.src = "images/button_min.jpg";
	btnText.innerHTML = "Click to Reduce";
	contentPanel.style.width = "990px";
	document.location.href = "#content";
}

function reduceContent() {
	var leftPanel = document.getElementById("vtLeftPanel");
	var contentPanel = document.getElementById("vtContentPanel");
	var rightPanel = document.getElementById("vtRightPanel");
	var btnPicture = document.getElementById("vtButtonExpandReducePicture");
	var btnText = document.getElementById("vtButtonExpandReduceText");
	
	leftPanel.style.display= "block";
	rightPanel.style.display= "block";
	btnPicture.src = "images/button_max.jpg";
	btnText.innerHTML = "Click to Expand";
	contentPanel.style.width = "630px";
	document.location.href = "#top";
}

function manageContent() {
	var statusBtn = document.vtExpandBtnStatus;
	
	if ( statusBtn == 0 ) {
		document.vtTopContentStatus = 0;
		expandContent();
		statusBtn = 1;
	}
	else {
		document.vtTopContentStatus = 1;
		reduceContent();
		statusBtn = 0;
	}
	
	document.vtHistoryStatus++;
	document.vtExpandBtnStatus = statusBtn;
}

function goBack() {
	var numPages = document.vtHistoryStatus;
	history.go( 0 - numPages );
}

function addPageToHistory() {
	var status = document.vtTopContentStatus;
	
	if( status == 0 ) {
		document.vtTopContentStatus = 1;
		document.vtHistoryStatus++;
	}
}