Validate user input as a valid ssn.

[davtech]

Ok here is my latest chalenge. I have a table in a set with a social security number field and the field rules for simple mask, 000-00-0000 is set. On my form when a user wants to enter a new claim they are prompted for a SSN from an action script (prompt for text), I have a default text of ###-##-#### but there is no gurantee of correct entry. If the entered value is not found in the table a new record is started and the SSN field on the form is pre-filled with the value entered at the preceeding prompt. I set the text property of the field to do this. If the SSN is entered at the prompt without dashes it is entered into field the same way and does not get modified by the table's field rules like I had hoped. It will modify the value if manually entered.

1. Is there a way at the prompt to validate for a valid SSN entry?

2. Is there a way to add the dashes like a mask?

3. If the above two are not possible is there a way to use the field rules when the value is set to the field on the form?

4. Is there another way to do this?

[Jay Talbott]

Re: Validate user input as a valid ssn.

When you say "valid SSN entry" do you mean that it is in the correct format (000-00-0000) or are you trying to match SSA's rules regarding numbers being in the correct range (from Wikipedia.com:

Currently, a valid SSN cannot have an area number between 734 and 749, or above 772, the highest area number which the Social Security Administration has allocated.[15]. This should not be confused with Tax Identification Numbers which include additional area numbers[16].

There are also special numbers which will never be allocated:

Numbers with all zeros in any digit group (000-xx-####, ###-00-####, ###-xx-0000).[17]
Numbers of the form 666-xx-####, probably due to the potential controversy (see Number of the Beast).[17]
Numbers from 987-65-4320 to 987-65-4329 are reserved for use in advertisements.[18]
The Administration publishes the last group number used for each area number.[19] Since group numbers are allocated in a regular (if unusual) pattern, it is possible to identify an unissued SSN that contains an invalid group number. Despite these measures, many fraudulent SSNs cannot easily be detected using only publicly available information.

Anyway, my advice would be to:
check length; number must be 9 digits
strip out all characters using remspecial and rebuild it with something like:
substr(remspecial(number_entered),1,3)+"-"+substr(remspecial(number_entered),4,2)+"-"+substr(remspecial(number_entered),6,4)

I hope this helps.
Jay

[Tom Cone Jr]

Re: Validate user input as a valid ssn.

Greg, the data entry mask field rule only kicks in if the field value is entered from the keyboard. It sounds as though you are getting unformatted input from the user and then using a script to populate the field in your table. Data entry from the action script will not cause the mask field rule to kick in and format the string for you. As Jay suggests you're going to have to reformat the string yourself. This is challenging because of all the different ways the user can supply incorrect input.

[davtech]

Re: Validate user input as a valid ssn.

Thank you Jay and Tom for your help. My biggest concern was getting the SSN value entered correctly in the database in the correct format ###-##-####. I'm going to file Jay's notes on the SSA's rules for future use. So my solution was the following for anyone that may be interested.

User is given a text prompt requesting a SSN entered without dashes. This value is stored in a variable and then tested by the following function I wrote.

FUNCTION ValidateSSN AS C (SSNValue AS C )
If isnumber(ssnvalue) = .t. .AND. len(SSNValue) = 9 then ' String consists of only numbers, "1234" and is the proper length.
ValidateSSN = substr(SSNValue,1,3) + "-" + substr(SSNValue,4,2) + "-" + substr(SSNValue,6,4)
Else
ValidateSSN = "" ' Returning an empty string indicates invalid SSN.
end if
END FUNCTION


This function verifys that the user did in fact enter a 9 digit number only. If this is the case the dashes are added and the result returned. If there is a problem a result of "" is returned indicating an error. If the user follows the directions correctly we now have a variable containing a properly formatted SSN value.

[Jay Talbott]

Re: Validate user input as a valid ssn.

Even though the user is prompted to enter the SSN without dashes, you can make the process more user-friendly by allowing dashes and then stripping them out.
Using the dashes makes checking the data entry easier for the user, and allowing, but not requiring the dashes will cover just about everybody.
Use the remspecial() and allow dashes. I think you will be better off.
Jay

[davtech]

Re: Validate user input as a valid ssn.

You have a good point Jay, thanks, I will do that.

[Tim Kiebert]

Re: Validate user input as a valid ssn.

You can also use the mask() function. Also as Jay mentioned if you throw remspecial() into the mix you can allow users to add dashes or spaces.(sometimes it is convenient to enter the data as you see it on a hard copy so you can very it has been entered correctly) However, if you have users that actually 'follows the directions correctly' you are a fortunate devleoper. :)

[B]FUNCTION ValidateSSN AS C (SSNValue AS C )[/B]    
     SSNValue [B]= [/B]remspecial(SSNValue)
     If isnumber(ssnvalue) = .t. .AND. len(SSNValue) = 9 then [COLOR=Blue]' String consists of only numbers, "1234" and is the proper length.     [/COLOR]
     ValidateSSN = mask(SSNValue,"   -  -    ")
     Else
    ValidateSSN = "" [COLOR=Blue]' Returning an empty string indicates invalid SSN. [/COLOR]    
     end if    
[B]END FUNCTION[/B]

[davtech]

Re: Validate user input as a valid ssn.

The mask() does make for cleaner code. Yeah I'm always amazed at how users can do things that I would never expect. :)