Hi,
Im using zen-cart 1.3.9b and i have created a custom template (called sdmc if it helps to name any file paths).

I have tried searching but found no answer (or atleast one i can properly understand).

I have created a custom field on my create account page and i would like to know how to make this field mandatory.
The instructions i used to create this field are located here

I have tried looking at the code to try and figure it out by myself but i dont get anywhere!

Any help would be great.

Thanks