Validate SSN data for all zeros or ones in text box

Posted on 2008-10-09
Last Modified: 2012-05-05
Hi, I'm trying to figure out how to validate data that users enter into input fields on a web form.  Basically, the users would be entering SSN# into the system but the system should prevent them from entering all zeros or any of the same digits or sequential numbers.  For example, the system should validate if the users enter data as one of the following:

333-333-333 on

Please let me know if you can think of an efficient way of handling all these permutations.
Thanks a lot for your time and assistance.
Question by:LISCNY
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LVL 69

Expert Comment

by:Éric Moreau
ID: 22683437
is it canadian SSN? if this is the case, the last digit is a check digit and can be used to validate that the whole number is valid.

Author Comment

ID: 22683888
In this case, I'm referring to data in US.  Would you please elaborate what you mean?  
Basically, I need generic validation for any numeric data input into the system.  There should be a function that would check if the data entered in a text field contains all zeros, 1s, 2s, etc.  
There may be another function created that would check against the value entered in the field to prevent users from entering sequencial numbers.
LVL 69

Expert Comment

by:Éric Moreau
ID: 22685373
In Canada, you can apply a formula to the first 8 digits of a SSN to validate the last one is valid. I don't know if US SSN are the same (a little Google search makes me think that it is not the same thing).

Accepted Solution

brrrdog earned 300 total points
ID: 22690606
I would use a RegularExpressionValidator....

Here's a place where you can get a couple of different regular expressions for a valid SSN:

I noticed the expression above does cover 000-000-0000, but not 555-555-5555.  A regular expression to do that would either need a lot of "ORs" or lookahead/lookbehind, neither of which is easy/clean.  So I would also use a CustomValidator in addition to the regular expression validator.  That way the regular expression validator will give you some client side validation for 99% of the cases and then the CustomValidator would let you write some very simple server side code to make sure all the digits aren't the same.
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LVL 14

Assisted Solution

raja_ind82 earned 200 total points
ID: 22693429
Here is the simple javascript validation for SSN. is this you want?



  <TITLE>M.Raja's Validation </TITLE>

      <script language ="javascript" >

    function validateSSN( strValue ) {


DESCRIPTION: Validates that a string contains a 

  valid social security number(XXX-XX-XXXX). 



   strValue - String to be tested for validity



   True if valid, otherwise false.


var objRegExp  = /^\d{3}\-\d{2}\-\d{4}$/;


  //check for valid SSN

  return objRegExp.test(strValue);


function isValidSSN(value) { 

    var re = /^([0-6]\d{2}|7[0-6]\d|77[0-2])([ \-]?)(\d{2})\2(\d{4})$/; 

    if (!re.test(value)) { return false; } 

    var temp = value; 

    if (value.indexOf("-") != -1) { temp = (value.split("-")).join(""); } 

    if (value.indexOf(" ") != -1) { temp = (value.split(" ")).join(""); } 

    if (temp.substring(0, 3) == "000") { return false; } 

    if (temp.substring(3, 5) == "00") { return false; } 

    if (temp.substring(5, 9) == "0000") { return false; } 

    return true; 


//function used to validate the inbox starts here

function  frm_validation()






			alert("Please enter your SSN");


			return false;


		else if(!(isValidSSN(txtID.value)))


			alert("Not a valid SSN");


			return false;


		 alert("valid SSN");

	return true;






<form name="frm" method="post">

  <input type="text" name="txtID">

  <input type="button" name="btnSubmit" onclick="Javacript: frm_validation();" value="ValidateSSN"><Br>





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Expert Comment

ID: 22698095
raja_ind82's javascript validation is fine if you wanted to add that in ADDITION TO a custom validator so that the all cases of the SSN can be validated on the client side.  All validation should always be done on the server side (which is automatic with .net validators if you check Page.IsValid).  Supplementing (not substituting) javascript validation is done for performance and convience of the client.  But javascript validation is easily bypassed, so it should only be done when server side validation already exists.

Author Comment

ID: 22901721
Thank you all for participating in this question.  They were all good solutions but I have derived with the attached solution below that addresses my issue.
Private Sub btnValidate_Save_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnValidate_Save.Click

If CStr(Me.txtDUNCDC.Value).Trim().Length = 9 And ValidateNumericData(txtDUNCDC.Value) = False Then

                lblError.ForeColor = Color.Red

                Me.lblError.Text = "Incorrect Entry, please review and correct the data."



Protected Function ValidateNumericData(ByVal value As String) As Boolean

        Const seqNumber = "123456789"

        Dim lastDigit As String

        Dim countLen As Integer

        Dim compareData As String

        Dim i As Integer

        If value = String.Empty Then

            Return True


            countLen = value.Length

            lastDigit = value.Substring(countLen - 1)

            For i = 1 To countLen

                compareData += lastDigit


            If compareData.Length = 9 Then

                If value.Equals(compareData) Then

                    Return False

                ElseIf value.Equals(seqNumber) Then

                    Return False


                    Return True

                End If


                Return False

            End If

        End If

    End Function

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Expert Comment

ID: 22902297
Just out of curiosity, are you using other .net validators (requiredfield, compare, etc) and the validationsummary control along with them?  If so is there  a reason you chose not to use a customvalidator?

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