Validate form field for numbers only

[bvarvel]

I have the following code:

 // check for zip
 if (document.form1.zip.value == "") {
 invaliddata += "\n - Zip is missing.";
 }

This tests that something exists. What I'd like to do is alter this to test that 5 numbers(zipcode) and only 5 numbers are entered. Can anyone help?

[c-double]

check this out
http://www.peterbailey.net/fValidate/download/

[bvarvel]

Thanks... but that's more than I need.

I've managed to get it to something like this:

 
 function checkForm() {
 var invaliddata = "";
 digits="0123456789"
 
 for(i=0; i<5; i++) {
    var charac = document.form1.zip.charAt(i);
    if (digits.indexOf(charac<0)) {
    invaliddata += "\n - Zip is missing.";
    }
    }
 
 }
 </script>

But this gives me the following error:

Error: document.form1.zip.charAt is not a function

All I'm trying to do is validate a zip code... surely someone has done this before?!?!?

[vgarcia]

Regular expressions to the rescue!

function checkForm() 
{
 var invaliddata = "";
 var zipCheck = /^\d{5}(-\d{4})?$/;
 
 if (!zipCheck.test(document.form1.zip.value))
 {
    invaliddata += "\n - Zip is missing.";
 }
 
}

That should validate a zip code in either the 5-digit format or the 5+4 format.

[bvarvel]

Once again v-man... you are the man! Thanks!

[vgarcia]

You may also want to change the error message too. My code will check for both a missing zip code and an improperly formatted one.

[bvarvel]

Vinnie -

You wouldn't happen to have an expression to check for a phone number would ya? Also - have any handy useful links so I can learn more about these?

[vgarcia]

Phone number regular expression:

^[\\(]{0,1}([0-9]){3}[\\)]{0,1}[ ]?([^0-1]){1}([0-9]){2}[ ]?
[-]?[ ]?([0-9]){4}[ ]*((x){0,1}([0-9]){1,5}){0,1}$

(this also checks extensions, for example (407)555-5555x1234).
And a great regular expression resource: http://regexlib.com/

[bvarvel]

OK - now THAT'S a handy website! Thanks again.