UE File Upload overwite error

This could be on my part because I don't know a lot about php. I can upload a file just fine and name it to a session variable but if I do it again and want to overwrite it it creates a second file with the same extension. For example it will create two files:

picture1.jpg
picture1.jpg.jpg

Code:
<?php
// WA_UploadResult1 Params Start
$WA_UploadResult1_Params = array();
// WA_UploadResult1_1 Start
$WA_UploadResult1_Params["WA_UploadResult1_1"] = array(
'UploadFolder' => "images/attractions/",
'FileName' => "".$_SESSION['attractionpic'] ."",
'DefaultFileName' => "",
'ResizeType' => "0",
'ResizeWidth' => "0",
'ResizeHeight' => "0",
'ResizeFillColor' => "" );
// WA_UploadResult1_1 End
// WA_UploadResult1 Params End
?>
<?php
WA_DFP_SetupUploadStatusStruct("WA_UploadResult1");
if($_SERVER["REQUEST_METHOD"] == "POST"){
WA_DFP_UploadFiles("WA_UploadResult1", "fileupload", "0", "", "false", $WA_UploadResult1_Params);
}
?>

Could somebody please help me as I don't want it to be named [FileName] but rather the session variable. Thanks in advance.

if you are cgoing to set the file name using a session:
'FileName' => "".$_SESSION['attractionpic'] ."",

make sure the name in the session does not include the extension.

other wise leave the ddefault:
'FileName' => "[FileName]",

if you leave the default as in the above example, you can select the option to rename the new file if it already exists, and the extension will handle the renaming for you.

The session variable doesn't contain the filename. I don't want the file to be named the same thing as the users computer's filename at all.

the only time I have seen the double extension like you describe has been if the file name setting includes the file extension.

where is the value for the session variable being set?

add the following code to the page to display the session variables value:
<?php echo($_SESSION['attractionpic']); ?>