user form data search

Hello,
I prepared the attached file to make a search in a sheet for Partnumber field. The program is almost finished. But the program will be used so often with a barcode reader. When the barcode reader scans the partnumber it automatically hits tab button. So the selection goes directly from textbox to commandbutton. I want the program make a search when the selection goes from textbox to commandbutton and also selection automatically should go to textbox again.(with selecting all text in the textbox.)
The program will make a search when selection goes from textbox to command button. But it doesn't setfocus again to textbox.
You can check commandbutton_click procedure because when you click comandbutton it makes search and setfocus to textbox with selecting text inside in it.I want this when tab button is hitted when the cursor is on textbox. (When the cursor goes from textbox to command button with tab button.)
Can anybody help me with this problem.
Thank you!!1