create a workflow for travel request form

I think your scenario is:

List A

-Create a workflow to update the list C

List B

-Create a workflow to update the list C

how? sorry I am new to nintex.

how? sorry I am new to Nintex. I am still trying to understand. Have any suggestions on how to improve also? 

Thanks

I created a workflow for list a and b. Both of them connecting to the main form. the main form is being updated, but I keep on getting an error. I do not know what I am doing wrong.

I am trying to get one form right now to update on the main form.

You could use the Update Item Action to update the items your list C.  However, there would need to be some sort of connective tissue that would allow you to identify you are updating the correct list item.  LIke a date the travel occured or name.  You are probably going to need two different workflows to identify when an item needs to be created or updated in List C.  Unless List C is already created and you are just updating data within it.  The Update Item & Create Item are two different actions you can perform.  Another thought, do you have Nintex Forms?  If so, why not just make one form and hide portions based on your needs.  

I got it to work! I used copy item in my workflow for the two forms I wanted the information to be copied in them.  ** Make sure that you copy the exact name of the columns** if not it will not work.