Expenditure value

Hi,

   Can someone help me with my concern.. I need to know on where should i navigate or what should i do in order to change the value of the expenditure from positive to negative.

   E.g. when project number mmmmmm was viewed in the expenditures > expenditure inquiry > project, the value of the project for expenditure E.EEEE.000000.E is positive 1000.

    My concern is how can i be able to change the value of the expenditure so that it could have a negative amount? If changing the existing expenditure value is not possible, maybe we could also try to add additional expenditure which contains a negative amount.