Let me please try again.

I have a Main Form with one of the buttons called Viewing the database. When I press this button Form 2 is loaded. On this Form I have a DataGridView who show's me all the entry from a tabel from the database. The DataGridView it look's like I described you on the last post.
On the Form 2 I have text boxes for all this: line, station, error, by, problem and data (txtline, txtstation, txterror, txtby, txtproblem, txtdata). Also have one button called Search.
Let us presume that i'm entering on txtstation letter X and then I press Search button. The DataGridView is filtered correctly and it's showing me the ID 4 and station X (please see tabel from the post above).
When I'm double-clicking ID 4 to see that entry, Form 3 it's loading with that entry. The problem is that the Form 3 is loading ID 1 not 4.
I hope it's clear now