Compare 2 sheets - output in sheet 3 - Excel

Hello,

I have 2 sheets. For example:

Sheet 1:

A2 = 777
B2 = 5

A3 = 438
B3 = 4

A4 = 555
B4 = 3

Sheet 2:

A60 = 777
B60 = 4

A1233 = 438
B1233 = 4

I want Output in Sheet 3 like this:

A1 = 777 (In Sheet 3 only if Match Sheet1's A == Sheet2's A and Sheet1's B != (is NOT) Sheet2's B)
B1 = 5 (Value from Sheet 1 - B2)
C1 = 4 (Value from Sheet 2 - B60)



So when it matches A3 to A1233 it checks if corresponding value in B is same, if it is same (see B3 = B1233 when A is matched), it will NOT output anything in Sheet 3.

If it cannot find corresponding for A in sheet 2 it will output like this in Sheet 3:

A2 = 555
B2 = 3
C2 = null


Help appreciated.

Thank you.

Excel 2003.