Formula where result on Sheet 2 is generated from data on sheet 1

Try this again.
Paste on sheet 2 column c then drag.

=IFERROR(IF(INDEX(Sheet1!C:C,MATCH(1,INDEX((Sheet1!$A:$A=Sheet2!$A1)*(Sheet1!$B:$B=Sheet2!$B1),),0))<>"",INDEX(Sheet1!$B:$B,MATCH(1,INDEX((Sheet1!$A:$A=Sheet2!$A1)*(Sheet1!$B:$B=Sheet2!$B1),),0)),"BLANK"),"")

finalazy, Once again many thanks.