function showhide(trigger, hider, meldingdicht, meldingopen){
	if(document.getElementById(hider).style.display == 'none'){
		document.getElementById(trigger).innerHTML = meldingopen;
		document.getElementById(hider).style.display = 'block'
	}else{
		document.getElementById(trigger).innerHTML = meldingdicht;
		document.getElementById(hider).style.display = 'none'
	}
}