Display GridView Selected Row Details in Popup using C# in ASP.Net

Hi All, Good Morning....

I made one gridview display (S.No ,empID,Name,Dept etc) and another one i made POPUP grid  in when iclick gridview row command for display all the details about Employees, the first girdview having more 5000 rows ,if click row number  4000 ,the pop gird displaying employees details, But main grid row coming to top row .i want stay page display 4000 rows,How can achive that ,

Please help me to complete my task ,

Thanks & Regards,

Venkat