Quick ereg_replace question

Hi, I need a regular expression which will eliminate all characters except numbers, period, and +, -, *, or / I am currently using: $new_value = ereg_replace('[^0-9\.-/+*]', "", $value); However, this seems to eliminate - as well. Any help would be appreciated. Also, any good references for regular expressions? Thanks, Grant -- Grant Rutherford Iders Incorporated 100-137 Innovation Drive Winnipeg, MB, Canada R3T 6B6 http://www.iders.ca tel: 204-779-5400 ext 36 fax: 204-779-5444 ================================ Iders Incorporated: Confidential ================================ Note: This message is intended solely for the use of the designated recipient(s) and their appointed delegates, and may contain confidential information. Any unauthorized disclosure, copying or distribution of its contents is strictly prohibited. If you have received this message in error, please destroy it and advise the sender immediately by phone, Email or facsimile.