c# Datatable

Question

first Datatable Contains:

Name    No   RollNo
gopal    1       
abc      2   
abd      3 

So Here I want  following output:
Name    No   RollNo
gopal    1      1      
abc      2      2
abd      3      3 

Means Copying One Column Value To Another column In Same Datatable... 
Please Help ME.....