confusion in selection parameters

hi all,

we want 2 lists

1. a list of po with good receipt done but invoice not parked

2. a list of po with gr done, invoice parked but not posted

these lists should also include gr of partial quantities

we have tried me2n with selection parameters we101 and rechnung

with selection parameter we101, report lists po with no goods receipt

with selection parameter rechnung, report lists po with good receipts value = posted invoice value.

we are confused with selection parameters, which ones to use for our requirement?

or are the reports giving wrong results?