Info record update check box in Po

Hi,

We are working in ECC 6.0 envirnmoment and our project is trying to explore the functionality of PIR. The problem is I am not able to see info record update check box in the material data tab of the PO. I did not get any configuration in SPRO to make that field visible/ invisible. Please help me to for making this field visible at the time of PO creation in transcaction code me21n.