Error: uncaught exception: Permission denied to get property

[optikalefx]

full error:

Error: uncaught exception: Permission denied to get property HTMLDocument.getElementById

 

I have a page, with 2 iframes on that page (left and main)

I have a button on left that reads text from a textarea on main

That button uses an onClick event handler to envoke this function:

function upButton() {
var JSVar = (parent.main.document.getElementById("myTextArea").value);
}

 

When you submit the button to do some stuff, it reloads main.

But you when you click submit again, you get the error i said above...

 

I understand if there was a security issue but all my frames src's are on the same domain.  And if they didnt allow getElementById then why would it work once?

 

I also know that all the variables being sent are fine, because they are echoed using php, and alerted using javascript.

 

so what is this error and why is it being so mean?