function navi_prev(){
	if(document.getElementById('sub_infotainment').style.visibility == 'visible'){
	document.getElementById('infotainment_img').src = 'style/infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/_mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_4.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_off.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'hidden';
	document.getElementById('sub_clanarea').style.visibility = 'hidden';
	document.getElementById('sub_communityarea').style.visibility = 'hidden';
	document.getElementById('sub_mediaarea').style.visibility = 'visible';
	}
	else if(document.getElementById('sub_clanarea').style.visibility == 'visible'){
	document.getElementById('infotainment_img').src = 'style/_infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_1.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_on.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'visible';
	document.getElementById('sub_clanarea').style.visibility = 'hidden';
	document.getElementById('sub_communityarea').style.visibility = 'hidden';
	document.getElementById('sub_mediaarea').style.visibility = 'hidden';
	}
	else if(document.getElementById('sub_communityarea').style.visibility == 'visible'){
	document.getElementById('infotainment_img').src = 'style/infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/_clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_2.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_off.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'hidden';
	document.getElementById('sub_clanarea').style.visibility = 'visible';
	document.getElementById('sub_communityarea').style.visibility = 'hidden';
	document.getElementById('sub_mediaarea').style.visibility = 'hidden';
	}
	else{
	document.getElementById('infotainment_img').src = 'style/infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/_communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_3.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_off.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'hidden';
	document.getElementById('sub_clanarea').style.visibility = 'hidden';
	document.getElementById('sub_communityarea').style.visibility = 'visible';
	document.getElementById('sub_mediaarea').style.visibility = 'hidden';
	}
	return
}

function navi_next(){
	if(document.getElementById('sub_infotainment').style.visibility == 'visible'){
	document.getElementById('infotainment_img').src = 'style/infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/_clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_2.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_off.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'hidden';
	document.getElementById('sub_clanarea').style.visibility = 'visible';
	document.getElementById('sub_communityarea').style.visibility = 'hidden';
	document.getElementById('sub_mediaarea').style.visibility = 'hidden';
	}
	else if(document.getElementById('sub_clanarea').style.visibility == 'visible'){
	document.getElementById('infotainment_img').src = 'style/infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/_communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_3.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_off.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'hidden';
	document.getElementById('sub_clanarea').style.visibility = 'hidden';
	document.getElementById('sub_communityarea').style.visibility = 'visible';
	document.getElementById('sub_mediaarea').style.visibility = 'hidden';
	}
	else if(document.getElementById('sub_communityarea').style.visibility == 'visible'){
	document.getElementById('infotainment_img').src = 'style/infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/_mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_4.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_off.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'hidden';
	document.getElementById('sub_clanarea').style.visibility = 'hidden';
	document.getElementById('sub_communityarea').style.visibility = 'hidden';
	document.getElementById('sub_mediaarea').style.visibility = 'visible';
	}
	else{
	document.getElementById('infotainment_img').src = 'style/_infotainment.jpg';
	document.getElementById('clanarea_img').src = 'style/clanarea.jpg';
	document.getElementById('communityarea_img').src = 'style/communityarea.jpg';
	document.getElementById('mediaarea_img').src = 'style/mediaarea.jpg';
	document.getElementById('navigation_left_img').src = 'style/navigation_left_1.jpg';
	document.getElementById('navi_rol_switch_img').src = 'style/navi_rol_switch_on.jpg';
	document.getElementById('sub_infotainment').style.visibility = 'visible';
	document.getElementById('sub_clanarea').style.visibility = 'hidden';
	document.getElementById('sub_communityarea').style.visibility = 'hidden';
	document.getElementById('sub_mediaarea').style.visibility = 'hidden';
	}
	return
}