mssql case sensitivity

mssql is case sensitive..

while selecting...i got problem...

SELECT * FROM YEMM_OUTMAIL INNER JOIN YEMM_OUTMAIL_ACK ON YEMM_OUTMAIL.EMAILID = YEMM_OUTMAIL_ACK.EMAILID WHERE YEMM_OUTMAIL.TIMEIN>=1177257600937 AND LOWER(YEMM_OUTMAIL_ACK.RECEIPIENT)='johnson@yahoo.com'

i can run in sql analyzer..but not in my coding...

what goes wrong

Intermediate-SQL syntax error: UPPER or LOWER function not allowed

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so the collection return to node is blank...

i cannot see anything in my table