Validating forms - examples?

Hi,

I want to validate forms. I want to check the following.
* Has the user given a valid e-mail address?
* remove all leading and trailing spacebar-hits
* Check if only text has been inputted in a textfield
* if a valid date is given
* Check if only numbers have been inputted in an input field
* all other checks I may have left out.

Thanx in advance,
Dj Mouse

Go and see the form validation article....

http://hotwired.lycos.com/webmonkey...?tw=programming

------------------

SR -
shiju.dreamcenter.net

Web developer from GOD's own country!!!!

SR,

Thank you man! I'm already checking out those lessons on webmonkey. If you have some more of these links, please send me/e-mail them to me.

Thanx!

Dj Mouse

SR,

I do have another question.
I looked at the code at Webmoney and now I'm trying to build my own validatechecker with the ereg() function. Here's what I'm trying to do:

I want the users to enter a valid "postcode".
A postcode contains exactly 4 leasing digits and 2 trailing letters, i.e.
1023DE or 1023 DE are valid postcodes
,but
12345 SED is not valid even as HDSK 12 is not valid.

I tried the following code, but it won't work.

function ValidPostcode($formname) {

if (!ereg("^[0-9]{4,4}[ t]{0,9}[[:alpha:]]{2,2}$",$formname) {
echo "No valid postcode!";
return false;
} else {
return true;
}

}

Do you have any suggestions?

Thanx,
Dj Mouse

Hi,

Can I make a suggestion. Everything that you have requested in your original message can be done in JavaScript. Save yourself a lot of hassle by doing it client side.

Falcon

Javascript has its plus sides but not for form field validation. I apologize if this offends someone. Using javascript to validate form fields is a newbie approach and a bad idea as a web developer.

More specifically, client-side data validation is very insecure, since it is very simple for BAD PEOPLE to by-pass your validation just by turning off JavaScript. Then they can enter values into your form that can trick your server side code and/or database software into doing whatever evil things they want.

Always do your data validation server-side.

Now, back to the question at hand:

djmouse, is that a space that's allowed between the digits and the letters, or is it any whitespace character (tab, space, etc.)?