Help With Cursor

hi,

i am pretty new with t-sql, cursors, and stored procs, so please bare with me. i am trying to update a table where
num1,num2,num3, and num4 represent certain percentages based on the first select counts. i am looking at the breaktimes and if those breaktimes are in certain interval, i am trying to set the breaktype field to 'SOMETHING'.

USE crap

DECLARE @BreakDate datetime(8), @ProductID int(4), @dp1 numeric(9), @dp2 numeric(9), @dp3 numeric(9),
@dp4 numeric(9), num1 numeric(9), num2 numeric(9), num3 numeric(9), num4 numeric(9), @event varchar(1024)

SET @BreakDate = '11/30/2004'
SET @ProductID= 4
SET @dp1 = 21600
SET @dp2 = 43200
SET @dp3 = 64800
SET @dp4 = 86400

SELECT COUNT(CASE WHEN BreakTime >= 0 AND BreakTime < @dp1 THEN 1 END) AS SC1,
COUNT(CASE WHEN BreakTime >= @dp1 AND BreakTime < @dp2 THEN 1 END) AS SC2,
COUNT(CASE WHEN BreakTime >= @dp2 AND BreakTime < @dp3 THEN 1 END) AS SC3,
COUNT(CASE WHEN BreakTime >= @dp3 AND BreakTime < @dp4 THEN 1 END) AS SC4
FROM DenInt
WHERE BreakType = 'SOFT'
AND BreakDate = @BreakDate
AND ProductID = @ProductID

SET num1 = SC1 * 0.1
SET num2 = SC2 * 0.1
SET num3 = SC3 * 0.1
SET num4 = SC4 * 0.1

DECLARE cCan CURSOR
FOR
SELECT *
FROM DenInt
WHERE BreakDate = @BreakDate
AND ProductID = @ProductID
ORDER BY BreakTime


OPEN cCan

FETCH cCan INTO @event

WHILE @@FETCH_STATUS = 0

BEGIN
IF num1 > 0 AND BreakTime >= 0 AND BreakTime < dp1

UPDATE DenInt
SET BreakType = 'SOMETHING'
WHERE DIGridID = DIGridID

END

CLOSE cCan

DEALLOCATE cCan


however, when i run the code above it returns

Server: Msg 170, Level 15, State 1, Line 4
Line 4: Incorrect syntax near 'num1'.
Server: Msg 170, Level 15, State 1, Line 22
Line 22: Incorrect syntax near '='.
Server: Msg 137, Level 15, State 1, Line 38
Must declare the variable '@event'.


what am i doing wrong? thanks for the help in advance