//turn divs off and on
//defaults the first div to be seen
var lastDisplayed = 'overview';
function hideDiv(element_id) {
	if (document.getElementById) { 
		document.getElementById(element_id).style.display = 'none';
	}
}


function showDiv(element_id) {
	if (document.getElementById) { 
	document.getElementById(element_id).style.display = 'block';
	}
}

function showHideTab(element_id) {
	hideDiv(lastDisplayed);
	showDiv(element_id);
	lastDisplayed = element_id;
	
}




//toggle small divs visibility
function showHideSubDiv(element_id) {
	if(document.getElementById(element_id).style.display=='none') {
		showDiv(element_id);
	} else {
		hideDiv(element_id );	
	}
	
}


//selected button stays as selected bg image 
var lastBtn = 'overviewBtn';
function unactiveBtn(element_id) {
	if (document.getElementById) { 
		document.getElementById(element_id).style.backgroundImage = 'url(/images/site-images/unselected_btn.gif)';
	}
}

function activeBtn(element_id) {
	if (document.getElementById) { 
		document.getElementById(element_id).style.backgroundImage = 'url(/images/site-images/selected_btn.gif)';
	}
}

function showActiveBtn(element_id) {
	unactiveBtn(lastBtn);
	activeBtn(element_id);
	lastBtn = element_id;
	
}