https://www.csr-consulting.pl/wp-content/themes/csrconsulting/assets/js/validation.js?ver=9.0

1$(document).ready(function() {
2    $("#send_message").click(function(a) {
3		
4        a.preventDefault();
5        var b = !1,
6            c = $("#name").val(),
7            d = $("#email").val(),
8            e = $("#phone").val(),
9            f = $("#message").val();
10        if ($("#name,#email,#phone,#message").click(function() {
11                $(this).removeClass("error_input")
12            }), 0 == c.length) {
13            var b = !0;
14            $("#name").addClass("error_input")
15        } else $("#name").removeClass("error_input");
16        if (0 == d.length || "-1" == d.indexOf("@")) {
17            var b = !0;
18            $("#email").addClass("error_input")
19        } else $("#email").removeClass("error_input");
20        if (0 == e.length) {
21            var b = !0;
22            $("#phone").addClass("error_input")
23        } else $("#phone").removeClass("error_input");
24        if (0 == f.length) {
25            var b = !0;
26            $("#message").addClass("error_input")
27        } else $("#message").removeClass("error_input");
28        0 == b && ($("#send_message").attr({
29            disabled: "true",
30            value: "Sending..."
31        }), $.post("email.php", $("#contact_form").serialize(), function(a) {
32            "sent" == a ? ($("#submit").remove(), $("#mail_success").fadeIn(500)) : ($("#mail_fail").fadeIn(500), $("#send_message").removeAttr("disabled").attr("value", "Send The Message"))
33        }))
34    })
35});