reference - event object attributes
<p>Regarding the code below, how does the interpreter know that event has attribute .keyCode.  This code works, I just don't undertand completely why, and more so were is this documented.  How does it know what type of object event is.  What if I would have called it 'e' or 'e1'.  Where is the mehtod prototype f1(Event) documented?</p>

<pre><code>function b0(event) 
  {if (event.keyCode==13) 
    {i4(); 
    return false;}} 


function o5('f4b_',b0); 

o5(a,b){document.getElementById(a).onkeypress=b;}
</code></pre>

<p>were the element id a is an input text box.</p>
