Question

I have a text box in which the SSN number is inserted by user the TexBox has a default value as 'XX-XX-' and then he enters four digit number after ‘XX-XX-‘ only. I have javascript but when he press tab the text in TexBox i.e ‘XX-XX-‘ is get selected and it Flush all the selected text. I want to restrict it to enter only after ‘XX-XX-‘ eg: XX-XX-1234 how to do?

.aspx page:

<asp:TextBox ID="txtInsuredSSN" runat="server" Text="XX-XX-" MaxLength="10" onkeydown="return validateSSN(event);" />

Javascript:

function validateSSN(key) {

            //getting key code of pressed key
            var keycode = (key.which) ? key.which : key.keyCode;
            var phn = document.getElementById('<%#txtInsuredSSN.ClientID %>');
            if (phn.selectionStart < 6)
                return false;
            //comparing pressed keycodes
            if ((keycode < 48 || keycode > 57)) {
                if ((keycode > 95 && keycode < 106) && phn.value.length < 10)//if num lock is on
                {
                    return true;
                }
                else if (keycode = 8 && phn.value.length > 6) { //check for backspace
                    return true;
                }
                else {

                    return false;
                }
            }
            else {
                //Condition to check textbox contains ten numbers or not
                if (phn.value.length < 10) {
                    return true;
                }
                else {
                    return false;
                }
            }
        }

Plz suggest any solution?

Answer 1

use a label for the hard coded prefix, something like :

<label>
<span class="frmlabelleftfloat">SSN: xx-xx-</span>
<asp:TextBox ID="Last4OfSSN"  runat="server" ValidationGroup="ssnValidation" MaxLength="4"></asp:TextBox>
<span class="failureNotification">*</span>
<asp:RegularExpressionValidator ID="regexpssn" runat="server" ControlToValidate="Last4OfSSN"
    ValidationGroup="ssnValidation"     Display="Dynamic" ForeColor="Red" ErrorMessage="Should be 4 Digits"
    ValidationExpression="\\d{4}?$">   </asp:RegularExpressionValidator>
</label>

you need to verify that regex though.