How do I implement a widget on my form?

I found a form ( 

 i want to implemente in my website; how do i do that????

I think you're referring to the demo form in the page for the Calorie Intake Calculator widget: https://widgets.jotform.com/widget/calorie_intake_calculator 

Here is also the link to the demo form: http://form.jotformpro.com/form/52220713451948 

You may add the widget to your form by following the steps on this guide: How-to-Add-a-Widget-to-your-Form

You can also clone the demo form by following this guide: How-to-Clone-an-Existing-Form-from-a-URL

Hope this helps.