function change(galname){
	var imgname=galname+"arr";
	if(document.getElementById(galname).style.display=="none"){
		document.getElementById(galname).style.display="block";
		document.getElementById(imgname).src="graphics/darr.png";
	}else{
		document.getElementById(galname).style.display="none";
		document.getElementById(imgname).src="graphics/rarr.png";
	}
}