WorkSheet Selection Change and Vlookup

I have a sheet (Sheet1) that has a product code entered, Column C.
The product description is in the same sheet in Column D.

I set up a sheet to manually enter the product codes and their descriptions ( Product Codes).
Column A is the Product Codes, and Column B the Descriptions.

If I enter an Product code into Sheet1 Column C, and there is an already entered Product Code in the product code sheet along with a description, I want the description to display after exiting the sheet1 product code in Column D.
I cannot formulate the cells, as not 100% codes are manually entered, and the user needs to sometimes manually enter both the code and he description.
What code would be best to accomplish this?

Thanks for the reply, the code seems pretty straight forward to analyse, but i cannot get it to work.
I get no errors, but no result also for some reason.
Tried ensuring events were enabled, but did nothing also.

Sheet name is identical.
Range is good.
Target column is correct.
??

Fixed with:

Please Login or Register  to view this content.

Needed to include 'WorkSheet Function' to get it to work.
Also had to add error trap if user enters an unmatching code, to allow for manual entering of description.