Something like this will work:

DECLARE @spid_table TABLE (spid smallint)

DECLARE @spid smallint,

 @kill nvarchar(11)

INSERT INTO @spid_table

SELECT spid FROM master..sysprocesses

WHERE dbid=DB_ID(db_name()) AND spid <> @@spid

WHILE (SELECT count(spid) FROM @spid_table) > 0

BEGIN

 SET @spid = (SELECT TOP 1...