IF AND statement does not work in excel 2013

Can someone help with this formula:
"IF" statement does not work in excel 2013:
=IF(AND(NOT(ISBLANK("B"&ROW())), (NOT(ISBLANK("B"&ROW() - 1)))),
SUM((INDIRECT("B"&ROW()) - (INDIRECT("B"&ROW() - 1)))),)