How to remove the mandaory option for the filed Closing date in the Oppotun

Hello Experts,,

We are using CRM 2007. In Opportunity Transaction the closing date field is mandatory by default. I want to remove the mandatory option for the Closing date field. For this Transaction there is no incompletion procedure.

Please suggest how to remove the mandatory option for the filed Closing date in the Opportunity.

Regards,

Mallik Kosuru