fill textbox with corresponding value

Dear All
can please review my code in the userform to do the following
the combobox1 is list of product from Waiting list sheet in column A
combobox2 is listed corresonding batch for product selected in combobox1
combobox3 is list number of shift from Ref sheet
combobox 4 is list run time from ref sheet
textbox1 is show value corresonping to product and batch slected in combobox 1 & 2 from
waiting list in column E

its work good now many thanks Dear Alphafrog

can please explain the code that can i modify to other if i understand it

Can please review this code for add buttom
its give me error with this line Set ws = Worksheets("Attendance")

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very good
its work good now

please last question i forget
if i need to make this code for add button all the time add the data to range of cell B1:B6 but give me message that will data present will be changed
how can make it ?

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look to my attched file
want add data only in cell highlighted with yellow color every time i press add button but give me alert message first

Originally Posted by AlphaFrog

I don't know what that means.

thank you Dear Alphafrog about your help