function considerChangingExpiryFocus() {
	if (!document.getElementById) {
		return;
	}
	var drop = document.getElementById('wpBlockExpiry');
	if (!drop) {
		return;
	}
	var field = document.getElementById('wpBlockOther');
	if (!field) {
		return;
	}
	var opt = drop.value;
	if (opt == 'other') {
		field.style.display = '';
	} else {
		field.style.display = 'none';
	}
}

function updateBlockOptions() {
	if (!document.getElementById)
		return;

	var target = document.getElementById('mw-bi-target');
	if (!target)
		return;

	var addy = target.value;
	var isEmpty = addy.match(/^\s*$/);
	var isIp = addy.match(/^(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}|:(:[0-9A-Fa-f]{1,4}){1,7}|[0-9A-Fa-f]{1,4}(:{1,2}[0-9A-Fa-f]{1,4}|::$){1,7})(\/\d+)?$/);

	var anonymousRow = document.getElementById('wpAnonOnlyRow');
	if( anonymousRow ) {
		anonymousRow.style.display = (!isIp && !isEmpty) ? 'none' : '';
	}

	var autoblockRow = document.getElementById('wpEnableAutoblockRow');
	if( autoblockRow ) {
		autoblockRow.style.display = isIp && !isEmpty ? 'none' : '';
	}

	var emailblockRow = document.getElementById('wpEnableEmailBan');
	if( emailblockRow ) {
		emailblockRow.style.display = isIp && !isEmpty ? 'none' : '';
	}
	
	var hideuserRow = document.getElementById('wpEnableHideUser');
	if( hideuserRow ) {
		hideuserRow.style.display = isIp && !isEmpty ? 'none' : '';
	}
}