Reordering grid Columns in Server Side

[Vinodh B]

GridColumnCollection cols = grid.MasterTableView.Columns;
GridColumn c = cols.FindByUniqueName(columnName);
if (c != null){ 
    int start = c.OrderIndex; 
    for (int i= start; i < cols.Count; i++)  
    { 
        c = cols[i]; 
        if (i < cols.Count - 1)   
            c.OrderIndex = i+1;
        else     
            c.OrderIndex = start;  
    }
}

the above code doesn't work when reordering columns through server side. I have written the above code in 
pageload event . I also tried by setting the various properites like ReorderColumnsOnClient=false but it 
doesn't work . 

Kindly suggest alternatives