Video:-

Steps:-

If you want to create terms and conditions check box, please follow below steps

1) First create one new field for this by clicking on the “+”.

2) Switch to advanced mode

3) Just create one field with Column name: “termsandconditions” or something you like

4) Attribute type: Text

5) Attribute size:10 (your choice)

6) in Field type: select MULTIPLE CHOICE

7) Now you will get options below of it, Select “Options (one value;name pair on each line – example: 1;Blue)“

9) Then in text area just type “True;” or “1;” or “agree;”

10) Please type the error message Error message:

10) Then click on the ok button.

Now that check box become a required input user must checked. Else it will show error message.

Source : http://devnet.kentico.com/Knowledge-Base/Web-parts—Controls/How-to-create-check-box-in-BizForm-that-is-require.aspx

Enjoy while coding..!