You can't use RowCreated to add a client-side script to the GridView control to get the value 
from a column located in the selected row because the created row's cells haven't been data-bound 
when the event is triggered. Instead, use the RowDataBound event. The following example gets 
the value from the second cell of a row when the row is selected by pressing the left 
mouse button on a row:

    void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.Cells != null && e.Row.Cells.Count > 1)
        {
            e.Row.Attributes.Add("onClick", "alert('Selected value: " +
    e.Row.Cells[1].Text + "')");
        }
    }