Refresh textbox Event

i chose enter event coz the previous control is a search textbox that's why calling of form would be activated with no keypress in the next textbox control, i tried textchanged but it just triggers when there is changes on the textbox enter event is most ideal but my problem is it cant be refreshed to be used to the next line. is there any other approach for putting multiple lines in one transaction as per item sales.

i have a datagridview unbound.
1 button add new
6 textbox search,description,dosage,qty,selling price,amount
search is a filter for the pop up form displaying choices of items to choose and passing
it to the line then input qty and first line will be complete and when button addnew is clicked first line will be moved to the dgv then all textbox will be cleared to start a new line. that's where my problem comes. when try searching again the event on the description is not activating. is there any alternative approach for inserting multiple lines before saving to database. i am new to c# and glad if you will contribute to my learning. thanks