delete rows from excel file

[santosh_tamse]

hi all
how to delete a row from excel file using Apache POI in Java Server Pages & how to shift a next row up after deleting a previous row.
how to solve out of memory error while reading a excel file.is it possible by increasing Jvm heap size, if yes then how
while reading an excel file it gives invalid header signature error plz tell me how it can be solved.
its very urgent
plz send me response as fast as possible.
plz do reply
thanks in advance