Stored Procedure

Question

Hi there

 

I am new to software development and have a test project I am working on. I have been trying to create a sql stored procedure and C# to insert data into a header table and a detail table. I need to be able to save multiple rows in the detail table which must be linked to a single header row id as per the picture below. The stored procedure I have created works but only saves one line in the header table and one in the detail table. As soon as I add a second line in the listview on my C# windows form and save it, it generates a id for the first row and another id for the second line.