how to check if letters are written in a textbox

hi,
my question ist with what command am i able to check if letters are written in a textbox?!
my problem is, that i only wnat numbers in this textbox and if letters are written in it, the script has to give out a failure message...
i hope you can help me!
thanx a lot...

There are two ways to do this:

1) check as the user hits submit and if it's invalid, don't allow them to continue and give an alert error message.
2) allow them to submit, then check it in PHP and give an HTML error message.

The 1st one would involved JavaScript, the second PHP. Since this is a PHP forum, I will answer #2.

If you want only numbers in the textbox, then you can check the $_REQUEST[], $_GET[], or $_POST[] variable using the is_numeric() function:

Code:

---

if (is_numeric($_REQUEST['textboxname'])) === false) {
    die("Only numbers are allowed in textboxname!");
}

---

If you want the 1st one, you would have to check it in JavaScript. I'm not sure how you'd do it, so you might want to check over there.

...But better to use JavaScript to check it - much faster

Sincerely,
Sergey Booyny
AlarIT programmer
http://www.AlarIT.com

merci :)
i will take the php source... i don't like java =)

Quote:

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Originally posted by Stylewriter
merci :)
i will take the php source... i don't like java =)

---

It's not Java. It's JavaScript. Two entirely differen't things.

And I have to agree with him. With the JavaScript, you can check it before the page is even submitted. Less loading, less bandwith, faster results, no possibility of loosing data.

But if you insist...

do both, some people have JS disabled.

What I do is make check all feilds with the PHP script, checking it very throughly giving a VERY simple error message.

JS is where I make the checking rather loose, but very user helpful, detailed error message as well as focusing on the incorrect input box.