regex strangely not allowing users to paste in textbox?

[Fog Juice]

I have the following code below which allows only alphanumeric characters for one text box, and then only numeric characters in the second. My problem is that in the first box, users can paste, which is perfectly fine, but in the second text box, they can't paste. I'd like it so that users could paste in each text box. Does anyone know why the second text box doesn't allow users to paste? It is quite odd to me and I'm not sure why.

 

One other thing is that the first textbox allows the % sign, but as far as I can see, the regex I have is only for alphanumeric characters.

<script>
function alphanumericscan(e, call){
var code;
if (!e) var e = window.event;
if (e.keyCode) code = e.keyCode;
else if (e.which) code = e.which;
var character = String.fromCharCode(code);
//alert(\'Character was \' + character);
    //alert(code);
    if (code == 8 || code == 9 || code == 37 || code == 39 ) return true;
if(call == "alpha") var AllowRegex  = /^[a-zA-Z0-9]+$/;
else var AllowRegex  = /^[0-9]+$/;

    if (AllowRegex.test(character)) return true;    
    return false;
}
</script>

Letters and numbers only: <input onkeypress="return alphanumericscan(event, 'alpha');" /><br />

Numbers only: <input onkeypress="return alphanumericscan(event, 'numonly');" />

[gizmola]

You are not detecting when the ctrl key is being pressed, so even though ctrl-v is a special combination, the keycode for v fails your numeric only regex, which defeats the paste functionality when using a key combination.  Unfortunately, if you allow this, you will bypass your key by key checking.  Even now you can see this is in action, by copying something that would not be legal into your paste buffer (try foo!!!!) and paste it into your text fields and you'll see that it bypasses your regex restriction.

[Fog Juice]

You are not detecting when the ctrl key is being pressed, so even though ctrl-v is a special combination, the keycode for v fails your numeric only regex, which defeats the paste functionality when using a key combination.  Unfortunately, if you allow this, you will bypass your key by key checking.  Even now you can see this is in action, by copying something that would not be legal into your paste buffer (try foo!!!!) and paste it into your text fields and you'll see that it bypasses your regex restriction.

 

What I don't understand though is why does pasting work in the first textbox, but not the second? They are both using the same functions, same key codes.

[gizmola]

It's because your first regex allows letters.  So it accepts the 'v'.