MS ACCESS using text box to add records

[d great one]

Hi guys. Sorry, I don't know where to put the thread.
I'll go on with the problem.

So I'm trying to create a database.

ok, so in example i made few tables. which are related to each other (relational database model).

so i made a relational, one-to-many.
in example primary key mainkey, is related to foreign key to another table.
In my form design, I tried making a text box. I tried linking the text box value which will add to the record of mainkey to all the table the mainkey is involve.
I tried using SQL commands. So when I click a button, it will add the value of what's inside the text box to a new record.

I'm lost here, and need help. I tried lots of researching, which didn't help me at all.

I got this error message when I execute the command.

microsoft office access can't append all the records in the append query.

microsoft office access set 0 field(s) to null due to a type conversion failure, and it didn't add 1 record(s)
to the table due to key violations, 0 record(s) due to lock violations, and 0 record(s) due to validation rule violations.