function swap_img( v ){
	if(document.getElementById(v).src.indexOf('plus')>=0)
		document.getElementById(v).src = document.getElementById(v).src.replace('plus', 'minus')
	else	document.getElementById(v).src = document.getElementById(v).src.replace('minus', 'plus');
}

var im= new Array();;
for(i=1; i<=6; i++){
  im[i] = new Image(); 
}
im[1].src = "/images/mi_plus.gif";
im[2].src = "/images/mi_minus.gif";
im[3].src = "/images/mi_item.gif";
im[4].src = "/images/mi_plus_sel.gif";
im[5].src = "/images/mi_minus_sel.gif";
im[6].src = "/images/mi_item_sel.gif";