Validating Column

[raul09]

Hi all,
In one Worksheet say Sheet1 I have 2 Columns namely Item No & Description with Data(rows).
In another worksheet i have the same 2 columns. My query is When i insert Item no in the second worksheet the Description Column should Validate itself from the data in the 1 st worksheet.

For Example
1st Worksheeet i have

Item No. Description
Item1 First Item
Item2 Second Item


So if in the second worksheet if i enter Item1 Under Item No Column the corresponding Description cell should filled with "First Item" as value automatically.
How can i achieve this?