I have two web app and one web form which I put it to two web app since it has the same form details. My question is how can I know or put a details that distinguish the web form submitted from two web app? Like someone submitted a form how can I identify which web app it submitted.
You can make a copy of the form and actually have different forms - which would be my way of doing it.
You can put a field* in the form that is hidden to the end user and set attribute e.g. , this way you will know which page the submission comes from.
If that doesn't work for you you can change the value with javascript depending on some other things shown on the page. If you need help with this, please post the two example pages that you have the form on.
*Note that you have to create the field in Web Forms and then edit the html on the backend.