function changeHier(arr, who, trg) {
	v = who.options[who.selectedIndex].value;
	t = who.form.elements[trg];
	t.length = 1;
	if(arr[v]) {
		l = arr[v].length;
		for(i=0;i<l;i++) {
			t.options[(i+1)] = new Option(arr[v][i][1], arr[v][i][0]);
		}
	}
}