some confirmation queries

Dear gurus,

MY client requirment is

Query 1

In production order If missing parts exists,during co11n it should give error message" missing part exists" confirmation not possible.

query 2:

in colln in goods movement tab.i am finding only backflushed materials.for issue based.even though if mb1a 261 has done,material should be visible in goods movement tab in colln along with backflused materials

query 3:

if mb1a 261 not done for all components in production order.system should give error message"mb1a 261 not done,confirmation not possible"

please suggesy your solutions and ideas

guna