Invalid character issue when running a script...

Hi All,

I'm trying to run following script in my designer, when I validate it there are no errors showing but when I run it, it throws me ORA-00911 invalid character error

sql('BIRDM_COE','DELETE  FROM lda_del_dups_p1 WHERE ORDER_TIME >= $LDA_START_DATE2 AND LDA_DATE = $LDA_START_DATE2');

$LDA_START_DATE2 is a variable of type datetime.

Any help would be greatly appreciated. Using BODI 3.1 and Oracle 11g.

Thanks.