userform textbox that searches column b

I have spent hours scrolling up and down this sheet looking for part numbers, so I created a userform with 2 textboxes. I want to enter a part number in the first textbox, and have the macro select the cell in column B that contains that part#. Then I will tab to the second textbox and enter a quantity. When I tab back to the first textbox, the quantity should paste into the next empty cell in the same row of the part# from textbox 1.

Textbox1 = 4110  Textbox2 = 500

	B	C	D	E
1	1010	25		
2	1020	14	15	
3	1030	19	11	
4	2020	100	10	
5	2030	23		
6	4100	67		
7	4110	24		
8	4150	24		
9	5010	10

On first tab, cell B7 would be selected, on second tab, 500 would be placed in cell D7.

I tried converting code from a similar post, but I ended up with extra code that crashes excel every time I try to save the file.

Any help is appreciated,

Thank you


(I already know how to create a userform and set up tab orders)