https://myrusakov.ru/js/sr.js

1function SR_IsListSelected(el) {
2	for (var i = 0; i < el.length; i ++)
3		if (el[i].selected || el[i].checked) return i;
4	return -1;
5}
6
7function SR_trim(f) {
8	return f.toString().replace(/^[ ]+/, '').replace(/[ ]+$/, '');
9}
10
11function SR_submit(f) {
12	f["field_email"].value = SR_trim(f["field_email"].value);
13	f["field_name_first"].value = SR_trim(f["field_name_first"].value);
14	if (f["field_name_first"].value == "Ваше имя") {
15		alert("Укажите Ваше имя!");
16		return false;
17	}
18	if ((SR_focus = f["field_email"]) && f["field_email"].value.replace(/^[ ]+/, '').replace(/[ ]+$/, '').length < 1 || (SR_focus = f["field_name_first"]) && f["field_name_first"].value.replace(/^[ ]+/, '').replace(/[ ]+$/, '').length < 1) {
19		alert("Заполните оба поля!");
20		SR_focus.focus();
21		return false;
22	}
23	if (!f["field_email"].value.match(/^[A-Za-z0-9][A-Za-z0-9\._-]*[A-Za-z0-9_]*@([A-Za-z0-9]+([A-Za-z0-9-]*[A-Za-z0-9]+)*\.)+[A-Za-z]+$/)) {
24		alert("Некорректный синтаксис email-адреса!");
25		f["field_email"].focus();
26		return false;
27	} 
28	return true;
29}