SQl First day of the Month

------------------Take First day of the Month ---------------

DECLARE @pInputDate          DATETIME
DECLARE @vOutputDate        DATETIME


set @pInputDate='4/25/2011' April Month


    SET @vOutputDate = CAST(YEAR(@pInputDate) AS VARCHAR(4)) + '/' +   CAST(MONTH(@pInputDate) AS VARCHAR(2)) + '/01'
    SET @vOutputDate = DATEADD(DD,0, DATEADD(MM, 0, @vOutputDate))
o/p= 1 April 2011