Trying to figure out the else if and not even coming close.

What I am trying to accomplish if texbox1 value = "stock: then it will take textbox1 and
fill the cell with a positive number . If textbox1 = 123456 or any number that is not "stock"
it would put that cell as negative. I need to do this for textbox 2 to textbox10

code below works to put it into the worksheet until I tried to play with the else .
As you can see totaly new to this 

NextRw = .Cells(.Rows.Count, 1).End(xlUp).Row + 1
        
        If UserForm1.TextBox1.Value = "stock" Then
        .Cells(NextRw, 1).Value = UserForm1.TextBox2.Value 
        Else
        .Cells(NextRw, 1).Value = UserForm1.TextBox2.Value* -1

        .Cells(NextRw, 2).Value = Date
        End With     
        .Cells(NextRw, 3).Value = UserForm1.TextBox2.Value
        .Cells(NextRw, 4).Value = UserForm1.TextBox4.Value
        .Cells(NextRw, 5).Value = UserForm1.TextBox5.Value
        .Cells(NextRw, 6).Value = UserForm1.TextBox6.Value
        .Cells(NextRw, 7).Value = UserForm1.TextBox7.Value
        .Cells(NextRw, 8).Value = UserForm1.TextBox8.Value
        .Cells(NextRw, 9).Value = UserForm1.TextBox9.Value
        .Cells(NextRw, 10).Value = UserForm1.TextBox10.Value
Thanks in advance if anyone wishes to help me.
Lewis