prevent postback form anchor click -> when we have onserverclick attribute

my aspx (html) code is like below :

this is first button (something that should act like a normal button , i used anchor because of some nice css job) :

                <p id="PaymentParag">
                    <a id="PaymentLink" onclick="SubmitForm();" name="PaymentLink" runat="server"
                        onserverclick="开发者_JAVA技巧PaymentLink_Click" alt="Payment" title="Payment"></a>
                </p>

as you see i have some server side code in onserverclick...

and this is another button :

<asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />

and my jquery code :

    function SubmitForm() {
        $('#form1').submit();
    }

    //>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

    $(function () {
        $('#form1').submit(function (e) {
            alert('a');
            var error = [false, false, false, false, false];

            var text1 = '';
            var text2 = '';

            var radtxtEmail = $find("<%= radtxtEmail.ClientID %>");
            text1 = radtxtEmail.get_value();

            var radMaskedtxtMobile = $find("<%= radMaskedtxtMobile.ClientID %>");
            text2 = radMaskedtxtMobile.get_value();

            var ErrorsInsideMessageBox = $('#ErrorsInsideMessageBox');
            ErrorsInsideMessageBox.html('');

            var FormMessages = $('#FormMessages');

            if (text1 == '' && text2 == '') {
                error[0] = true;
            }
            if (error[0]) {
                ErrorsInsideMessageBox.append(FormMessages.html());
                e.preventDefault();
            }
        });
    });

clicking on second button causes submit and related postback...

when error[0] = true we only have submit , not postback...

so , it seems every thing is normal about second button (regular asp.net button)

but my problem is about anchor (submit and postback)...

when i click it we have only postback , not submit , because of adding runat="server" and onserverclick="PaymentLink_Click"...

so i added onclick="SubmitForm();" for submitting form1...

but at this time i do n't know why we still have postback when error[0] = true -> e.preventDefault();

edit after comments :

i replaced that anchor by a link button like below :

 <asp:LinkButton onClientclick="SubmitForm();" ID="PaymentLink" runat="server" onclick="PaymentLink_Click"></asp:LinkButton>

but i don't know why linkButton does not couse submit (like anchor) so i forced to add onClientclick="SubmitForm();

after doing this i still have postback when error[0]=true;

how can i prevent this postback ?

thanks in advance

---

Update

Now understand what you say about.

Submit and post back is the same think.

This line totally confuse me. When you expect the onserverclick to run ? when there is a submit, that means a postback.

<a id="PaymentLink" onclick="SubmitForm();" name="PaymentLink" runat="server"
  onserverclick="PaymentLink_Click" alt="Payment" title="Payment">

I think that you need to change a little your flow logic of your page.