Remove Line From Text File

[asman]

I have 2 textbox :
Textbox1 to display a line on a text file (barcode.txt)
Textbox2 for input line/word

i want to remove line from list of lines, So if the line in textbox2 exists on that list (textbox1), to be remove from list, and file to be saved

i have a file barcode.txt with list:

qwerty
asdfgh
zxcvbg

If I write in textbox2 : asdfgh and if barcode.txt contains that line then remove it after saving to datagrid. so result need to be :

qwerty
zxcvbg

and on textbox1 it always displays the available lines in barcode.txt. how i do it?
help would be greatly appreciated. Thank you