character legnth

verN

echo ('<p><input id="seminarT "name="seminarT" type="text" size="60" value="'.$sem_title.'" onchange="checkInput()" /></p>');

function checkInput() {
var str = document.getElementByName("seminarT").value;
if ( str.Length > 10 ) {
alert("Please enter less than 20 characters");
}
}

i am using this code but nothing gets outputted when I type in more then 20 charaters. Any hellp will be good. Thanks

dougal85

Hmm, strange. I'd try length with a lowercase L. Other than that I'm not sure.

Also, btw, you know you can specify the maximum length in the HTML?

🙂

Weedpacket

dougal85 wrote:
Hmm, strange. I'd try length with a lowercase L. Other than that I'm not sure.

That would be it; Javascript identifiers are case-sensitive, and it's ".length" in this case.

And unless those are typos because the code was retyped instead of being copied, it's "document.getElementById()" and there's a missing " in the line being echoed.

verN

echo ('<tr>
<td width="150"><p><strong>Title of seminar:</strong></p>
<p><input id="seminarT" "name="seminarT" type="text" size="60" value="'.$sem_title.'" onchange="checkInput()" /></p></td>');

function checkInput() {
var str = document.getElementById("seminarT").value;
if ( str.length > 10 ) {
alert("Please enter less than 20 characters");
}
}

this works however i now want it to work when the user clicks submit button. The form already has onsubmit="return check()"

i changed the above to onsubmit but it didn't work instead i get a php error saying that the variable is undefined. What i need it to say is when the user clicks submit button in trhe form for a alert to appear rather then using onchnage use submit i tried this but it still doesn';t work

verN

help how to I get the above code to work as onsubmit

Thnaks

verN

HELP ANYONE!
im really stuck i do not know how to check that the user needs to input characters that are less than 50 chatacters using onsubmit

THANKS

dougal85

It would be easiest doing it the way I suggested.

However, if you insist on using JavaScript...

this works however i now want it to work when the user clicks submit button. The form already has onsubmit="return check()"

your function is called checkInput() but I think thats just a typo in your writing on the form.

I think the function needs to return true or false, then it will be submitted. sooo try...


function checkInput() {
    var str = document.getElementById("seminarT").value;
    if ( str.length > 10 ) {
        alert("Please enter less than 20 characters");
        return false;
    } else {
        return true;
    }
}

dougal85

Also, btw, your throwing the error if its greater than 10, but it says you want less than 20. and in your other post you said you wanted less than 50...

bradgrafelman

And also note that Javascript is easily bypassed with the click of a button these days (assuming it was even enabled/supported in the first place), so I hope you're not relying on Javascript as the end-all solution for length validation..