I have implemented the uploadify in my project and it is working fine in my end. But some of my friends could not from the other side. They are getting a javascript error at the status bar (they are using IE) which when clicked is giving

"spanUploadUploader" is undefined [Note : spanUpload is the span id being used]

Any ideas will be appreciated.

parameters being used :

$('#spanUpload').fileUpload({
'uploader': 'upload/uploader.swf',
'script': 'upload/upload.php',
'checkScript' : 'upload/check.php',
'fileExt' : '*.doc;*.pdf;*.txt;*.htm',
'fileDesc' : '*.doc;*.pdf;*.txt;*.htm',
'folder': 'documents',
'cancelImg': 'upload/cancel.png',
'multi' : true,
'auto' : true,
'buttonImg' : 'img/uploadbutton.png',
'hideButton' : true,
'buttonText' : 'Upload',
'displayData' : 'percentage'
});

Thanks you for your time.