InfoPath Dev

I have a problem with my DDL when populating the textbox. When i select from the DDL it populates the the Product Name, Product Number and Product Price based from the sharepoint list I also create a Quantity: (TextBox) for the computation Product Price: that will be populated to the Total Price the computation is:

fx: Quantity * @Product_Price

 but the problem is that i have three example product name: Ferrari, Lambo and Bugatti

When i select the Ferrari from the DDL the populated Product Price is 1,000,000 SGD and when i put in the Quantity: 2 at the Total Price: 2,000,000 correct!

 BUT

when i click the repeat section below and click LAMBO and the Populated Product Price: 150,000,000 SGD based from the SP list and when i add to the Quantity: i put "2" the Total Price is WRONG teh answer still 2,000,000SGD  it still computing from my first list (Ferrari) in my DDL list. I hope that you can help me into my problem.       

Hi:

You'll need to filter the data for your @Product_Price field. You should probably use the Filter Data button when you select the @Product_Price field in the formula editor. You want to select the @Product_Price where the Product Name field from your secondary data source is equal to the main data source field that contains the seleted product name, like Lambo or Bugatti... or Ferrari.

Hi Hillary, Great! it works thank you so so so much!

it works in this formula fx: Field1[@Product_Price = Field1]    

I have another question from the DDL issue Ms. Hillary, inside the DDL once I select a product from the three LAMBO, FERRARI and BUGATTI the senario is that once i select LAMBO can i disable the LAMBO from the DDL so that it will not be select again so that only 1 LAMBO in the repeating table (TextBox). Many Thanks.