JavaScript名称姓氏验证不起作用

Question

Hey guys ı want to validate name,surname etc in javascript.

var regex = /^[A-Za-z ]{1,20}$/;

When I typed harun(which is obviously true) but it gives false,When ı typed harun12 it gives false too.Can anyone tell me what am ı doing wrong with this code?

function check() {

            var name = document.getElementById('<%= txt2.ClientID%>');
            var surname = document.getElementById('<%= txt3.ClientID%>');

            var textregex = /^[A-Za-z ]{1,20}$/;
            alert(textregex.test("harun"));

            if ((name.value == '') || (textregex.test(name) == false) ) {
                $("#name_error").dialog("open");
                $("#txt2").val('');

            }
            if ((surname.value == '') || (textregex.test(surname) == false){
                $("#surname_error").dialog("open");
                $("#txt3").val('');

            }


        }

    });

        <asp:TableRow ID="TableRow2" runat="server">
            <asp:TableCell>Name:</asp:TableCell><asp:TableCell>
                <asp:TextBox ID="txt2" runat="server" />
                <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="txt2" />
            </asp:TableCell>
        </asp:TableRow>

        <asp:TableRow ID="TableRow3" runat="server">
            <asp:TableCell>Surname:</asp:TableCell><asp:TableCell>
                <asp:TextBox ID="txt3" runat="server"/>
               <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="txt3" />
            </asp:TableCell>
        </asp:TableRow>
    </asp:Table>

Answer 1

As per your comment name refers to dom object not it's value so use

alert(textregex.test(name.value)); 
//                       --^--

or

var name = document.getElementById('<%= name.ClientID%>').value;
//                                                        --^--

Update

if ((name.value == '') || (textregex.test(name.value) == false)) {
  //                                           --^--
  $("#name_error").dialog("open");
  $("#txt2").val('');
}
if ((surname.value == '') || (textregex.test(surname.value) == false)) {
  //                                                 --^--
  $("#surname_error").dialog("open");
  $("#txt3").val('');
}

Answer 2

Use this:

var regex = /^[A-Za-z1-9]{1,20}$/;
regex.test('text');//True
regex.test('text123');//True

What you are wrong, it is that the validation is only sure that you have alphabetic characters, so false damage when it contains numbers.

If you want to allow bank space uses like this:

var regex = /^[A-Za-z1-9\s]{1,20}$/;
regex.test('text123 ');//True
regex.test('text 123');//True
regex.test('text test2');//True