function pop_window (target_url, window_width, window_height, window_name) {
	window_width = format_numeric (window_width, 400);
	window_height = format_numeric (window_height, 400);
	if (window_name.length == 0) { window_name = "_new"; }
	if (target_url.length > 0) {
		var my_window = window.open (target_url, window_name, 'toolbar=no,' + 'location=no,' + 'directories=no,' + 'status=no,' + 'scrollbars=yes,' + 'resizable=yes,' + 'copyhistory=no,' + 'width=' + window_width + ',' + 'height=' + window_height);
		my_window.focus();
	}
}

function format_numeric (input_value, default_value) {
	if (isNaN(input_value) || input_value.length == 0) {
		return default_value;
	} else {
		return input_value;
	}
}