rounding off

hi friends !!!!!

in a invoice the total amount is say e.g Rs 100.69

here i want above total amount is in round like Rs 100 only

tell me in detail what r the condition types can i use and please give me respective REQUIREMENT ~~-ALT CAT TYPE -~~

ALT COND BAS VAL-ACCOUNT KEY

and where i have to maintain in pricing procedure

thanks in advance