comparison macro

Hi All,
Can anyone help me here please....
I need to compare the values of data on one sheet (sheet1) with that of another (sheet2) to see if there has been any changes between the sheets over the previous week. If a macro could go through my data on sheet1, compare cell-by-cell the data that's in sheet 2 and highlight in red font any cells that have different values that would be awesome.
The macro would need to leave the "fill color" of the cell as it was.

Any help much appreciated

Thanks

Beatrice