Linking two forms together help

[slowdeath007]

I am quiet new to using access and I would appreciate some help. I have one form inside of another which lets the user input a lot of data and based on what person is selected on the main form the data you entered is displayed. The problem is I don't know how to get to input into the table the ID of the person currently selected when you input data. If I input the data manually into the table it works fine since I have linked the master and the child fields. Please check the picture

[slowdeath007]

also the relations are here.Everything is displayed correctly but I have to write the ID manually.