Display Records in Random Order each time Select Query is executed in SQL Server

i want to display records randomly in gridview from database

 Eg :

             id      city            category   compname     rate

             1      newyork      Books          mediatech  1000

             2      newyork      Books          Info tech     1000

             3      newyork      Books          Sysmach      999

             4      newyork      Books          Wifi texh       0

now the data are displaying in descending order by rate wise and

there are two company booked  in same price which is 1000 . i want to display random which is

one day mediatech should be in top and next day info tech should be in top.