Re: This XML file does not appear to have any style information associated with it. The document tree is shown below.

We are starting to get out of my comfort zone but this might work

var text URLnull="xx";

if([checkbox field]=true,

"javascript:" &
"$.get('" &
$url &
"',function(){" &
"$.jGrowl('Warning! You have already Imported Standard detail records.', {life: 5000});" &
"});" &
"void(0);",

$URLONE
& "&rdr=" & urlencode($URLTWO)
& URLENCODE ("&rdr=" & urlencode( $URLTHREE)) )

But another way to go is simply this

if([checkbox field]=false,
$URLONE
& "&rdr=" & urlencode($URLTWO)
& URLENCODE ("&rdr=" & urlencode( $URLTHREE)) )

if you do that and the checkbox is true (ie already imported) , then the formula is null and the button will be blank with nothing to click on.