How to Close the Pending Purchase Orders

Hi

We have a lot of Pending Purchase orders aganist which we have recieved only a Partial Qty. Now we would like to close all these purchase orders. When i check in the Open Order Qty i am able to see the pending Qty but the same when i try to close with P4312. It is not displaying any Records.

So there is a lot of lines like this which display in the Open Order but not able to close.

Please suggest the process to close all these lines.

Thanks

Naveen