validate gridview Rows

Question

i have grid view rows which add dynamically by using one button control

 

 

i have to restrict the same data enter by user in one or more rows

 

by using javascript 

 

 

Eg: Gridview

 

1. Muthu       Kumar          anand

 

2.Muthu        Kumar          anand

 

 

 

if two datas are same it need to show alert using javascipt