MAcro to Compare two colums in different sheet and paste corresponding data.

Hi,

I have two excel sheet.
Sheet1 and Master sheet, I want a macro which can update the sheet1(whenever the data of Master sheet is changed) by comparing ColA of sheet1 with ColA of Master sheet.
ColA can be considered as master column, And I have 20 columns in use in both sheets. It would be great if come1 can help me out here.
And also column 2 of master is not nessary the same column in sheet1. It can be Col 3 in sheet1.

I guess no1 has an answer?

Please attach a sample book.