Help Form Reject Based on Time

[admin]

I need my form to reject the user upon submit if the time they are submitting the form is NOT 24 hours out from the pickup time they choose.<br /><br />I already have it set up to reject if they do not enter their ID number or do not enter a pickup time.<br /><br />If you know of an easy way to accomplish this, I would really appreciate the help.<br /><br />Here's a link to my form:<br /><br />http://www.plu.edu/~dining/meals_away.htm<br /><br />Thanks!<!--content-->