var f=document..loginForm; how can it work?

[John Davis]

I found this code in a JSP page. I don't have javascript experience and don't have a book, and I'm wondering how
var f=document.loginForm;
can work. I mean, there seems to be no reference to document or loginForm anywhere. So how can the expression document.loginForm be assigned to the f variable?

function doSubmit()
{
if (submitted)
return(false);
var f=document.loginForm;

if (f.username.value=="")
{
alert("You must enter an e-mail address.");
f.username.focus();
return false;
}

if (f.password.value=="")
{
alert("You must enter a password.");
f.password.focus();
return false;
}

submitted=true;
return(true);
//f.submit();
}

[Eric Pascarello]

var f variable can store stuff like this...
All it is doing is settig a global variable (f) to the form object.
It makes it easier to reference the form elements by not having to type in:
document.Forname.ElementName.value="blah"
instead you can do something like this
Elem = document.FormNane.ElementName;
I then can do this
Elem.value="Blue"; //change value
Elem.style.background="blue; //Change CSS properties
This was a basic explaination, and I am not sure I anwered your question!
Eric

[John Davis]

Eric,
Yes Eric, you answered my question very well!
Thanks for the help.
John Davis