Need to subtract values between previous and current row

Hi,<br /><br />I have a table that contains data like this:<br /><br />ID           ATIME (MM/dd/yyyy)<br />==         
====<brclear="all" />1            10/12/2006<br />2            10/14/2006<br />3            10/18/2006<br
/>4           10/22/2006 <br />5            10/30/2006<br /><br />Now I need a query that will subtract atime of row 1
fromrow 2, row2 from row3  and so on...<br /><br />Can anyone please help?<br /><br />Regards.<br /><br />-- <br
/>------------------------------<br/> Partha Guha Roy<br />***********************************************<br />Take
everythingyou like seriously, except yourselves.<br />- Rudyard Kipling