Accessing form elements and how I fell flat on my face

Oh dear, I thought, after something I’d asserted with all the confidence of an infallible man 
 turned out to be nonsense. In good faith I’ve always tried to encourage
 the use of nonproprietary HTML
 and client-side scripting. I’m especially hard on my colleagues, who get an earful 
 if they write proprietary code.

Recently my clever advice came back like a boomerang. I first told someone in a discussion
 to use this construct to access form elements.

document.forms("jmeno_formulare").elements("jmeno_prvku")

Does anything look odd, or more precisely proprietary, about it? I certainly didn’t think so. Within 
 an hour I’d stepped into Wonderland. A colleague and I happened to be reworking a web application,
 and because I practice what I preach, I used the construct above. Mozilla had an unpleasant surprise 
 for me. That bit of code simply couldn’t work.

The syntax above is a proprietary approach that works only in the Internet Explorer family of browsers.

The right approach

If we remember that the form elements will probably be represented in a
 collection, we can use these two approaches,

document.forms["jmeno_formulare"].elements["jmeno_prvku"]

or alternatively

document.jmeno_formulare.jmeno_prvku

Another good option is the DOM. We can
 give each form element an id attribute and then access the elements
 as follows.

document.getElementById("id_formularoveho_prvku");

So there I was preaching water and drinking wine. Once I’d sobered up, I’d proved to myself
 again how important it is to test code as well as talk about it.