Elseif Statement Find Next Empty Row

I have created a user form with a combo box and three text boxes. The drop down box is populated via the initialization of the form; code is posted below.

the "add item" names are names that are already on the worksheet in column 1. What i have done is used the command button "submit" to populate the information from the textboxes to the worksheet.

what i would ike to do is populate the empty cells below this area with the information that is in all three text boxes and the combo box. for the IF / elseif statments i have used the combo box as the condition. So the quandry is I cant input the information into the empty cells, i have tried a few things, my vba is very basic, as you can tell ihavent even DIM'd anything (i think that is another thread though :D )

here is the initialize code and below is the "submit button" code.



Private Sub UserForm_Initialize()
'sets values for text boxes
cbomaterialdiscription.Value = ""..........