How to move data from Sales order Line information to another document page Line.

Thanks for the Reply Slawek!
my requirement is to design a document page and call that page in sales line reference. When i entered the data in the sales order page then that data should moves into created page. I had tried this but i am getting only header information not the line data and here as follows that i had done. I called that page in sales line under Function Action and took a local function in Sales Order subform and written the code as

X.RESET;
X.INIT;
X.No := SalesHeader."No.";
X.INSERT(TRUE);

Y.RESET;
Y.INIT;
Y."No" := X.No;
Y."Line No" := SalesLine."Line No.";
Y.INSERT(TRUE);

Where X is created header and Y is created Line and i had X primary key as No and Y primary keys as No and Line No.
Thanks In Advance.