function AjaxFormCheck(field, value) {
	if (!value) {
		alert('Заполните поле ' + field);
		return;
	}	
	
	$.post('ajax.php', {mode: "check_register_field", field: field, value: value}, AjaxFormCheck_result);
}

function AjaxFormCheck_result(str) {
	str = str.split("|");
	if (str != 'ok') {
		field = str[0];
		mode = str[1];
		value = str[2];
		
		show_message(value, 5000);
	}
}