How it detects the difference between old xml file and new xml file

Hi there,

Am really astonished with one of the features of the lectora.

I have imported one external file to lectora named input.xml.

After that i have imported same file to my lecotra.

The message it shown was the file has been already imported to lectora.

Actually it should ask for replace the old file. when internal changes are made to the xml file it asks for replace.

When we import them without anychages second time it says "It has been already added".

Is lectora checks the internal contents of XML file while uploading.

Thanks and Regards

Vino