Rebate issue...guys

hi guys

I have an issue with rebate processing..

I created an agreement for material rebate.. After that i created sales order and delivery and pgi .. after that billing.. In Billing i got the condition type in Line item.. Till this is no problem

After that when i gone to change mode of agreement.. when i click on verification level it is showing message like

There is no sales volume for agreement 104

Message no. VK786

System Response

There is no sales volume for the agreement. No drill-down can be

displayed.

Kindly give me ur valuable solutions ...