Converting time into integer

Hi ,

I performing time claculations ,Is there FM to convert a field of type T into type Integer ?

i have 3 fields

tot begtime endtime

0.98 08:59 09:58

tot is of type Curr with 2 decimals,betime,endtime are of

T

i am getting problem when i am performing calculations like

tot = beg - end.

Regards.