[staticfire]

Hello all,

I just recently started learning Javascript to improve my web coding ability and i am currently studying form validation. I set this up so that the submit button only shows when the user has entered more than 200 characters. This script does not appear to be working

Code:

<script type="text/javascript">

 if (comment_form.comment.value.length > 200){

     document.write("<center><input type='submit' name='send' value='Send Comment'></center>");

}

</script>

Any help would be appreciated, Thank you.

[End User]

You may need to call your code on each onKeyUp() event so it checks comment_form.comment.value.length. Otherwise the code you've shown will only be called once (when the page is first opened). This will work:

Code:

<form name="comment_form">
<textarea name="comment" id="comment" onkeyup="checkCommentLength()"></textarea>
<center><input type='submit' name='send' value='Send Comment' ></center>
</form>
<script language="javascript">
     comment_form.send.style.visibility="hidden";

function checkCommentLength(){

  if (comment_form.comment.value.length > 5){
     comment_form.send.style.visibility="visible";
  }else{
     comment_form.send.style.visibility="hidden";
  }
}
</script>

[staticfire]

So i should perhaps make a function and call it in the keyup event of the textarea?

[End User]

See the code I pasted in above...it should work.

[staticfire]

Ok i just implemented that into my site and it's working fine. Thanks a lot

[scott2500uk]

just as a side note the above code may have problems running in FF or produce and error...

you should try using:

getElementById('send')

Code:

<form name="comment_form">
<textarea name="comment" id="comment" onkeyup="checkCommentLength()"></textarea>
<center><input type='submit' id='send' value='Send Comment' ></center>
</form>
<script language="javascript">
     comment_form.getElementById('send').style.visibility="hidden";

function checkCommentLength(){

  if (comment_form.comment.value.length > 5){
     comment_form.getElementById('send').style.visibility="visible";
  }else{
     comment_form.getElementById('send').style.visibility="hidden";
  }
}
</script>

[End User]

Originally Posted by scott2500uk

just as a side note the above code may have problems running in FF or produce and error...

What version of FF? The only browser I normally use is FF and it worked fine here.