correct way to use variables in the javascript DOM

Question

What is the correct way to format the document.formToSubmit.submit() line?

    var formToSubmit = 'postcomment' + id;

    alert( ''+ formToSubmit +'' );

    document.formToSubmit.submit();

The formToSubmit variable seems to be correct but the submit() does not work.

Answer 1

The formToSubmit is now a string not an object. Try this:

 var formToSubmit = document.getElementById('postcomment' + id);
 alert( ''+ formToSubmit +'' );
 formToSubmit.submit();

Answer 2

Simply put:

document.getElementById('postcomment' + id).submit();

Answer 3

Zyphrax is on the right track. You just need to remove "document." in the last line.

var formToSubmit = document.getElementById('postcomment' + id);
alert( ''+ formToSubmit +'' );
formToSubmit.submit();

The alert is working as expected since formToSubmit is now a DOM object and the message you're receiving is the appropriate string representation. If you want to check that you have the right form you could do:

alert(formToSubmit.id);

Answer 4

document['postcomment'+id].submit()

should also work