Error with DATE_DIFF in mysql

[fvckman]

I keep getting an error trying to implement DATE_DIFF in mySQL.I'm trying to get the number of days between "hm_date" and the present day, and have the number appear in a different field called "total_days".Doing this on servier-side, my code is getting an error: #1305 - FUNCTION naturan8_41q.DATE_DIFF does not exist\[code\]SELECT * FROM reg_add WHERE DATE_DIFF(hm_date,total_days)\[/code\]