[thelist] Simple Javascript field checking

[Christian Heilmann]

Brian Cummiskey wrote:

> john at johnallsopp.co.uk wrote:
>
>>>>
>>>> function checkEmail()
>>>> {
>>>>        if
>>>> (document.registrationForm.regEmail!=document.registrationForm.regEmail2) 
>>>>
>>>>        {
>>>>                alert ("Emails not the same");
>>>>                return false;
>>>>        }
>>>>        return true;
>>>> }
>>>>
>
>> <tr>
>>   <td>Email: </td>
>>   <td><input type="text" name="regEmail"></td>
>> </tr>
>> <tr>
>>   <td>Email (repeat): </td>
>>   <td><input type="text" name="regEmail2" onBlur="checkEmail();"></td>
>> </tr>
>>
>
>
> This is not a fail safe.  Theres a good chance I typo'ed the FIRST 
> email, not the second, so when i go back and change the first and 
> leave the 2nd alone, nothing gets checked.
>
> I would wait until the form is being submitted to check anything.
>
> <input type="button" onclick="checkform()"; />
>
> function checkform() {
>     if !(checkEmail())
>     {
>     alert "blah"
>     retrun false;
>     }
>     else
>     //submit the form...
>     document.registrationFrom.submit();
> }
>
>
> and even more so, the enitre thing fails if JS is disabled.
>
> Server-side is the only way to be certain.
>
Yes it is, but you can have both. What you should do to make it failsafe 
(of course with a backend script to fall back on) is to call your script 
onsubmit on the form not onclick of a button. Your example would make 
the button useless when there is no scripting available.