function showtab(which) {
	activetab(which);
	activepanel(which);
}
function activetab(which) {
	alltabs_off();
	idref = "t_" + which;
	if (document.getElementById(idref)) { document.getElementById(idref).className = 'active'; }
	
}
function activepanel(which) {
	allpanels_off();
	if (document.getElementById(which)) { document.getElementById(which).style.display = 'block'; }
}
function alltabs_off() {
	if (document.getElementById('t_tab1')) { document.getElementById('t_tab1').className = 'off'; }
	if (document.getElementById('t_tab2')) { document.getElementById('t_tab2').className = 'off'; }
	if (document.getElementById('t_tab3')) { document.getElementById('t_tab3').className = 'off'; }
	if (document.getElementById('t_tab4')) { document.getElementById('t_tab4').className = 'off'; }
	if (document.getElementById('t_tab5')) { document.getElementById('t_tab5').className = 'off'; }
}

function allpanels_off() {
	if (document.getElementById('tab1')) { document.getElementById('tab1').style.display = 'none'; }
	if (document.getElementById('tab2')) { document.getElementById('tab2').style.display = 'none'; }
	if (document.getElementById('tab3')) { document.getElementById('tab3').style.display = 'none'; }
	if (document.getElementById('tab4')) { document.getElementById('tab4').style.display = 'none'; }
	if (document.getElementById('tab5')) { document.getElementById('tab5').style.display = 'none'; }
}