/**
*	Navigation for anattitude
*
*/
hasprevious = true;
hasnext = true;

function doHoover( elid ){
	if(( elid == 'navprev' && (! hasprevious) )
		|| ( elid == 'navnext' && (! hasnext) )) return false;
	var image = document.getElementById( elid );
	image.src = "../images/" + elid + "-black.jpg";
	return true;
}	

function noHoover( elid ){
	if(( elid == 'navprev' && (! hasprevious) )
		|| ( elid == 'navnext' && (! hasnext) )) return false;
	var image = document.getElementById( elid );
	image.src = "../images/" + elid + "-grey.jpg";
	return true;
}

function goPrevious(){
	if( frames['iframe'].document.getElementById('previous') ){
		var urmel = frames['iframe'].document.getElementById('previous').href;
		frames['iframe'].location.href = urmel;
	} 
}

function goNext(){
	if( frames['iframe'].document.getElementById('next') ){
		var urmel = frames['iframe'].document.getElementById('next').href;
		frames['iframe'].location.href = urmel;
	} 
}

function enableImage( elid ){
	var image = document.getElementById( elid );
	image.src = "../images/" + elid + "-grey.jpg";
}

function disableImage( elid ){
	var image = document.getElementById( elid );
	image.src = "../images/" + elid + "-white.jpg";
}

function contentLoaded(){
	var canprevious = false;
	if( frames['iframe'].document.getElementById('previous') ) canprevious = true;
	var cannext = false;
	if( frames['iframe'].document.getElementById('next') ) cannext = true;

	if(canprevious != hasprevious){
		if(canprevious) {
			enableImage( 'navprev' );
		} else {
			disableImage( 'navprev' );
		}
		hasprevious = canprevious;
	}

	if(cannext != hasnext){
		if(cannext) {
			enableImage( 'navnext' );
		} else {
			disableImage( 'navnext' );
		}
		hasnext = cannext;
	}
}