function toggleDisplay( element )
	{
		if ( element && element.style )
			{
				if ( element.style.display != 'none' ) hideElement( element );
				else showElement( element );
			}
	}

function toggleDisplayById( elementId )
	{
		var element = document.getElementById( elementId );
		if ( element ) toggleDisplay( element );
	}

function showElement( element )
	{
		if ( element && element.style ) element.style.display = '';
	}


function hideElement( element )
	{
		if ( element && element.style ) element.style.display = 'none';
	}

function showElementById( elementId )
	{
		var element = document.getElementById( elementId );
		if ( element ) showElement( element );
	}

function hideElementById( elementId )
	{
		var element = document.getElementById( elementId );
		if ( element ) hideElement( element );
	}

function toggleClassName( element, class_name )
	{
		if ( 0 <= element.className.indexOf( class_name )) setClassName( element, '' );
		else setClassName( element, class_name );
	}

function toggleClassNameById( elementId, class_name )
	{
		var element = document.getElementById( elementId );
		if ( element ) toggleClassName( element, class_name );
	}

function setClassName( element, class_name )
	{
		if ( element ) element.className = class_name;
	}

function setClassNameById( elementId, class_name )
	{
		var element = document.getElementById( elementId );
		if ( element ) setClassName( element, class_name );
	}


function displayRequestedPopup()
	{
		var urlArray = window.location.href.split( '#' );

		if ( 0 < urlArray[1].length )
			{
				showElementById('popup_' + urlArray[1] );
				setClassNameById('nav_link_' + urlArray[1], 'selected' );
			}
				
	}