Blank cells are getting populated as null

[Banerjee]

Hi I am using excel 2003 to populate values for file uploading.

Now what I am doing is I am filling up the sheet and then saving the sheet as a tab delimited text .txt and then using a code I am extracting those values from the txt file.

The problem which I am facing is for any attribute if I am leaving the cell blank sometimes the value populated for that particular cell is a blank space and sometimes the value="null".

Please tell me what may be the possible reasons for this thing to happen and secondly how can I resolve the issue.

[Banerjee]

Please let me know if anyone has any idea regarding this. Its urgent