can i have someone sign electronically on the form?

Yes, you can achieve that by adding signature widget to your form. You can use Smooth Signature widget or E-Signature widget. 

Inside of this guide you can find how to add widget to your form: 

http://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form 

Hope this will help. Let us know if you need further assistance.