Error Message : Condition type is not maintained in the schema RM0002

HI Gurus,

I have created a new purchasing procedure as follows.

ZVATV : <b>Condition Schema</b>

VATV : <b>Condition Type</b>

VA : <b>Sch.Grp Vndr</b>

When I create the Purchase order, the above mentioned schema, ZVATV is automatically determined.

But when I create Contract, system throws an error message saying condition type VATV is not maintained in the schema RM0002.

I am very new to SAP, Kindly explain in very detail about this error message and ways to get rid of it.

If u have got any very detailed material about pricing kindly forward it to my mail id: gokul.p@gmail.com.

Thanks in advance.

~Gokul.