man i'am getting another problem

VB Code:
  1. lateness = pbRst!datereturned - pbRst!expecteddate
pbRst!datereturned = 5/30/2006 and pbRst!expecteddate =5/17/2006

when the above is exeuted lateness becomes 1/12/1900

how do i do o get the difference in number of days ie 13

thanks for your replies guys coz u r helping me a lot