Only Cyrillic input text form
javascript, jquery
Solution
Firstly, you should use encoding which supports Cyrillic characters (e.g. UTF-8) both for page and for scripts. Then, you may use regular expression to check:
$("input").keyup(function() {
this.value = this.value.replace(/[^а-яё]/i, "");
});
DEMO: http://jsfiddle.net/CSjkP/
Problem
How do I restrict input text into a web form textbox only Cyrillic characters?