MIRO tolerance limits

Hi guys,

We have to configure the following scenario.

Suppose PO rate is Rs 100. Upper limit for MIRO shall be 10% i.e. MIRO should be possible upto RS 110. Lower side MIRO shall be posted for any value i..e. even for Rs 1-00 also.

What are the tolerance keys to be maitained to achieve this functionality?

Thanks in advance

chintu