Compare two worksheet & insert

Dear ALL,

I have Excel 2007 worksheet, It has Four column CUST_ID, BLANK, CUST_ID2, EMAIL_ADDRESS

i want to compare CUST_ID & CUST_ID2, it should find the common records in CUST_ID & insert EMAIL_ADDRESS to respective common CUST_ID in BLANK column. please find attached file for more info.

I sincerely appreciate your help.


Thanks