Dynamically-generated hidden input fields

Hi there. I am dynamically creating hidden input fields in JS. As  
usual, IE is giving me problems. I can do this in FF and it works  
fine, but as soon as I attempt to access this in IE, it explodes:

<js>
var form = document.alertForm;
var count = form.length;

for (var i=0; i<count; i++) {
     // This works fine in IE - all fields print
     alert(form.elements[i].name+': '+form.elements[i].value);
}

// This does NOT work in IE, but does in FF
// 'call_method' is a hidden input that I create dynamically
alert(form.call_method.name+':: '+form.call_method.value);
</js>

Note, in the for() loop, 'call_method' displays its name and value  
just fine. But when I attempt to access it directly  
(form.call_method), it doesn't work in IE - I get an "Error on page"  
with the error being "Object expected", code 0. Anyone know of a work- 
around/solution for this?

Thanks,
~Philip