Calculation Combobox and textbox to locked textbox

[evinx]

hi all im new here and little noob with excel vba

im trying to make a form system that i can use at my work to make my work much easier
where i can collect information of my clients and what kind of installations they have on there building

i have a userform with:

Combobox1 (with text of sheet1 column A)(column B has the value of the text in column A)
textbox1 (where i can type the amount in KG)
textbox2 (here i need a result of calculation)

For example:
Combobox1=R410A (value is 2.088)
textbox1=2.4
textbox2=5.011

Combobox1 * textbox1 = textbox2

i cant figure it out how to
i use this code for my combobox1

Dim cell As Range
With Worksheets("Sheet1")
For Each cell In .Range("A2:A1000" & .Cells(Rows.Count, 3).End(xlUp).Row)
If Not IsEmpty(cell) Then Combobox1.AddItem cell.value
Next cell
End With

i hope someone can help me

 

[evinx]

oke i figured it out thanks for all reply

Private Sub Freontypes_Change()

    gwp.Text = Application.VLookup(Freontypes.value, Worksheets("Database Freon").Range("B2:C1000"), 2, False)

End Sub

Private Sub Freoninhoud_Change()
    If Freoninhoud.Text = "" Then
        MsgBox "Vul iets in"
        Exit Sub
    Else
     Co2.Text = CDbl(Replace(Me.Freoninhoud.Text, ".", ",")) * gwp.Text
    End If
End Sub