$_REQUEST Problem

I've a variable that can come with the GET and POST method, So I use
$_REQUEST to get it

When I use a simple href
href="myFile.php?myVar=value"
I have myVAr in the $GET and $_REQUEST arrays.

But when I pass throw a javascript function (to do some checks before to
call php)
href="javascript:myJsFunction('myFile.php?myVar=value',' ');"

and here is the javascript code
function myJsFunction(phpAction)
{
/// code for checks
document.forms[0].action=phpAction;
document.forms[0].submit();
}
I have myVar in $_GET but not in the $_REQUEST array
How can I have it in the request array