form validation no characters allowed

[azphoenix]

I would like to add code so that FirstName and LastName fields will only allow letters, numbers and underscores.

I found this code, but don't know how to edit the javascript below that works well with my existing form.

Any help would be greatly appreciated.

Thanks

-------------------------------------
var illegalChars = /\W/;
// allow only letters, numbers, and underscores
if (illegalChars.test(strng)) {
error = "The username contains illegal characters.\n";
}
------------------------------------



Don't know how to add the above to work with this...

<script LANGUAGE="javascript">
<!--
function validation(){
var path = document.mainform
if (path.password.value != path.password2.value){
alert('Your passwords didn`t match. Try again');
path.password.value = '';
path.password2.value = '';
return false
}
else if (path.password.value == '' || path.City.value == '' || path.Zip.value == '' || path.State.value == '' || path.Address.value == ''|| path.Telephone.value == ''|| path.FirstName.value == '' || path.LastName.value == '' || path.Email.value == ''){
alert('You must fill out the required fields.')
return false
}
else if (path.question.options[path.question.selectedIndex].value == '' || path.answer.value == ''){
alert('You must pick a question and fill out an answer for lost password.')
return false
}
else{
return true
}

}
//-->
</script>

[RSoftware]

Give this a try. You can't go wrong with good old RegEx!
If any names are wrong, change as needed.

Code: Select all

else if (!(path.FirstName.value.match(/[A-Za-z0-9_]/)) || !(path.LastName.value.match(/[A-Za-z0-9_]/))){
alert('You can't enter any special characters in the first name or last name fields!')
return false
}

[azphoenix]

I added that, with the complete version below. Doesn't seem to work because the form submits and ignores the added code.
I appreciate your help.


<script LANGUAGE="javascript">
<!--
function validation(){
var path = document.mainform
if (path.password.value != path.password2.value){
alert('Your passwords didn`t match. Try again');
path.password.value = '';
path.password2.value = '';
return false
}
else if (path.password.value == '' || path.City.value == '' || path.Zip.value == '' || path.State.value == '' || path.Address.value == ''|| path.Telephone.value == ''|| path.FirstName.value == '' || path.LastName.value == '' || path.Email.value == ''){
alert('You must fill out the required fields.')
return false
}
else if (path.question.options[path.question.selectedIndex].value == '' || path.answer.value == ''){
alert('You must pick a question and fill out an answer for lost password.')
return false
}
else if (!(path.FirstName.value.match(/[A-Za-z0-9_]/)) || !(path.LastName.value.match(/[A-Za-z0-9_]/))){
alert('You can`t enter any special characters in the first name or last name fields!')
return false
}
else{
return true
}
}
//-->
</script>

[RSoftware]

Sorry, poor logic on that! (unencapsulated OR)
This one looks like a mess of brackets, but its logic is good.


else if(!((document.getElementById("txtFirstName").value.match(/^(\w){1,}$/)) && (document.getElementById("txtLastName").value.match(/^(\w){1,}$/)))){alert("You can't use special characters in the First or Last name fields!"); return false;}


Replace "txtFirstName" and "txtLastName" with the ID attributes of the relevant text boxes.

-crosses fingers-

[azphoenix]

Thanks for the code; it works great!

Forever, in trying the code I discovered 2 scenarios that will cause me trouble that I forgot about.

(1) I need to allow for spaces in those 2 fields. For example, if the first name is "Mary Jo", it won't be allowed because of the space. Could potentially have that same issue with the last name too.

(2) I also need to allow for " ' " just incase someone's last name is "O'Neal" etc. I can do an asp replace function to " ` " on the post page before it goes to the database. I don't know if its possible, but it would be good if the java script code would only allow one " ' ". That way it won't submit if the user tries to add a nickname like John 'Jack'.

Again, thanks for the code and if there is a fix for the above 2 scenarios, I appreciate your help.

[RSoftware]

easy enough, replace the ^(\w){1,}$ regex with ^([a-zA-Z0-9'_ -]){1,}$ in both halves of the if.
I recommend reading up on RegEx syntax and the Javascript string::match function. They can prove invaluable in quickly validating user input.

[azphoenix]

Thank you very much. That's works great! I will do some reading up on that; thanks for the suggestion.

Is there a way to only allow the use of one " ' " or is that beyond the scope of what javascript can do?

Thanks again.

[RSoftware]

There seems to be no native way to do it, so below i've written a simple function to return the number of occurances of a string within another string. Enjoy ^^.

Code: Select all

function countStr(strSource, strTest){
return (strSource.split(strTest).length -1);
}

Then add the following elseif clause:

Code: Select all

else if(!((countStr(document.getElementById('txtFirstName').value, "'")<=1) && (countStr(document.getElementById('txtLastName').value, "'")<=1))){
alert("You can only use one apostrophe (') in the First or Last name fields!"); return false;
}

Hope that works!

[azphoenix]

Not sure if I added it correctly to the javascript. Below in red is what I added. If I had to guess, I didn't add the function part correctly.

<script LANGUAGE="javascript">
<!--
function validation(){
var path = document.mainform
if (path.password.value != path.password2.value){
alert('Your passwords didn`t match. Try again');
path.password.value = '';
path.password2.value = '';
return false

}
function countStr(strSource, strTest){
return (strSource.split(strTest).length -1);
}
else if (path.password.value == '' || path.City.value == '' || path.Zip.value == '' || path.State.value == '' || path.Address.value == ''|| path.Telephone.value == ''|| path.FirstName.value == '' || path.LastName.value == '' || path.Email.value == ''){
alert('You must fill out the required fields.')
return false
}
else if (path.question.options[path.question.selectedIndex].value == '' || path.answer.value == ''){
alert('You must pick a question and fill out an answer for lost password.')
return false
}

else if(!((document.getElementById("FirstName").value.m atch(/^([a-zA-Z0-9'_ -]){1,}$/)) && (document.getElementById("LastName").value.match(/^([a-zA-Z0-9'_ -]){1,}$/)))){alert("You cannot use special characters in your name. Please no nicknames.");
return false;
}

else if(!((countStr(document.getElementById('FirstName' ).value, "'")<=1) && (countStr(document.getElementById('LastName').v alue, "'")<=1))){alert("You can only use one apostrophe (') in the First or Last name fields!");
return false;
}
else{
return true
}
}
//-->
</script>

[RSoftware]

You have the function nested in your ifstatment as though it were a clause. Move it up outside the function:

function countStr(strSource, strTest){
return (strSource.split(strTest).length -1);
}
function validation(){
var path = document.mainform
if (path.password.value != path.password2.value){
alert('Your passwords didn`t match. Try again');
path.password.value = '';
path.password2.value = '';
return false
}

Nesting a function within another function is fine, it makes that function available only to the function within which it is declared.

Nesting a function within an if will just kill your if.
if syntax must follow: if - [else if] - [else] - end.

Keep going, you'll be a master in no time

[RSoftware]

also there appears to be a space after the ID of your marked elseif:
else if(!((countStr(document.getElementById('FirstName' ).value, "'")<=1)

This may or may not throw an error, but i recommend fixing.

[azphoenix]

You are brilliant! It works great.

I know enough about ASP in that I should of caught the nested if statement.

I wish I was the master in javascript like you. You have been a big help and I truly appreciate your assistance in this matter.

Take care!

[azphoenix]

One more question....Would you know why this javascript doesn't work in Firefox. I do have javascript enabled.

[RSoftware]

Is it just the most recently added function / if clause that is causing it not to work?

Does firefox raise an error? (Check the 'Tools' > 'Error Console' box.)

If there's an error there, post it and i'll see if i can work out the solution on that, otherwise, you can attach the page if you like and i'll see what i can do.

Cross-browser compatability is the bane of the internet coder!

For now, to work! ttyl =]