validate input

[tpeck]

I need to check the input of a textarea. I require the cursor not to allow input of anything except "n" or "N" or "y" or "Y".

I have this so far:

function validate() {
    var val = document.getElementById('textarea').value;
    if (/^\s*$/g.test(val)) {
        alert('Wrong content!');
    }
}

It checks for empty spaces I think.

How can it check for yes or no? (y or Y or n or N)

[Philip M]

<input type = "text" id = "textarea" size =  "1" maxlength = "1" onblur = "validate()">

<script type = "text/javascript">
function validate() {
var val = document.getElementById('textarea').value;
if (/[^yn]/gi.test(val)) {
alert ('Wrong content!  You must enter y or n');
document.getElementById('textarea').value = "";
return false;
}
}
</script>

It is a bad idea to name an HTML field "textarea". And why a textarea if the only valid entry is y or n?


Due to earlier signalling problems there are short-notice castrations in the Guildford area. - Train announcer at Wimbledon Station.

[tpeck]

Thanks Philip.

I have changed it to an <input> with the id="done":

<input type="text" class="Format4" id="done" name="done" size="1" maxlength="1" value="N">

It works!