Since im using Excel 2002 with no chance to upgrade can someone help me with the following

I currently have >> =IF(Sheet1!A:A=Sheet2!A2,SUMIF(Sheet1!C:C,Sheet2!C2,Sheet1!D:D),0)

I want the formula to sumif the number is 1 and the area is AREA1 or any other sequence

Any ideas ?

Sheet 1 has

Number Name Area Quantity
1 Name1 AREA1
1 Name1 AREA1
1 Name1 AREA2
1 Name1 AREA2
2 Name2 AREA1
2 Name2 AREA1
2 Name2 AREA1
2 Name2 AREA2
2 Name2 AREA2
3 Name3 AREA1
3 Name3 AREA1
3 Name3 AREA1
3 Name3 AREA2
3 Name3 AREA2
4 Name4 AREA1
4 Name4 AREA1
4 Name4 AREA1
4 Name4 AREA1
4 Name4 AREA2
5 Name5 AREA1
5 Name5 AREA1
5 Name5 AREA1
5 Name5 AREA1
5 Name5 AREA1
5 Name5 AREA1
5 Name5 AREA2
5 Name5 AREA2


Sheet 2 has

Number Name Area Quantity
1 Name1 AREA1 4
1 Name1 AREA1 70
1 Name1 AREA2 5
1 Name1 AREA2 11
2 Name2 AREA1 33
2 Name2 AREA1 5
2 Name2 AREA2 2
2 Name2 AREA2 3
3 Name3 AREA1 19
3 Name3 AREA1 14
3 Name3 AREA1 67
3 Name3 AREA2 87
4 Name4 AREA2 3
4 Name4 AREA2 1
4 Name4 AREA1 8
4 Name4 AREA1 3