I have some code which checks a value selected in a dropdown list and then runs a bit code to update some textbox values accordingly. The code is a bit long winded (sample section below) and I want to use a for next loop to run it instead. But I don't know how to reference the name of the textbox using the value from the drop down, i.e. If '5' is selected from the dropdown then Forms!tblItems!Month5.value will be populated and the other text boxes set to 0.

I'm sure this can't be too hard but I am quite new to VBA and don't know how to do this! Thanks in advance for any help.

Code:
If Forms!tblItems!PurchMonth.Value = 1 Then
        'CurrentProject.Connection.Execute "UPDATE tblItems SET Month1 = '" & Forms!tblItems![Total Cost].Value & "', Month2 = '0', Month3 = '0', Month4 = '0', Month5 = '0', Month6 = '0', Month7 = '0', Month8 = '0', Month9 = '0', Month10 = '0', Month11 = '0', Month12 = '0' WHERE EntryID = " & Forms!tblItems!txtEntryID.Value
            Forms!tblItems!Month1.Value = Forms!tblItems![Total Cost].Value
            Forms!tblItems!Month2.Value = 0
            Forms!tblItems!Month3.Value = 0
            Forms!tblItems!Month4.Value = 0
            Forms!tblItems!Month5.Value = 0
            Forms!tblItems!Month6.Value = 0
            Forms!tblItems!Month7.Value = 0
            Forms!tblItems!Month8.Value = 0
            Forms!tblItems!Month9.Value = 0
            Forms!tblItems!Month10.Value = 0
            Forms!tblItems!Month11.Value = 0
            Forms!tblItems!Month12.Value = 0
        ElseIf Forms!tblItems!PurchMonth.Value = 2 Then
        'CurrentProject.Connection.Execute "UPDATE tblItems SET Month1 = '0', Month2 = '" & Forms!tblItems![Total Cost].Value & "', Month3 = '0', Month4 = '0', Month5 = '0', Month6 = '0', Month7 = '0', Month8 = '0', Month9 = '0', Month10 = '0', Month11 = '0', Month12 = '0' WHERE EntryID = " & Forms!tblItems!txtEntryID.Value
            Forms!tblItems!Month1.Value = 0
            Forms!tblItems!Month2.Value = Forms!tblItems![Total Cost].Value
            Forms!tblItems!Month3.Value = 0
            Forms!tblItems!Month4.Value = 0
            Forms!tblItems!Month5.Value = 0
            Forms!tblItems!Month6.Value = 0
            Forms!tblItems!Month7.Value = 0
            Forms!tblItems!Month8.Value = 0
            Forms!tblItems!Month9.Value = 0
            Forms!tblItems!Month10.Value = 0
            Forms!tblItems!Month11.Value = 0
            Forms!tblItems!Month12.Value = 0
        ElseIf Forms!tblItems!PurchMonth.Value = 3 Then
        'CurrentProject.Connection.Execute "UPDATE tblItems SET Month1 = '0', Month2 = '0', Month3 = '" & Forms!tblItems![Total Cost].Value & "', Month4 = '0', Month5 = '0', Month6 = '0', Month7 = '0', Month8 = '0', Month9 = '0', Month10 = '0', Month11 = '0', Month12 = '0' WHERE EntryID = " & Forms!tblItems!txtEntryID.Value
            Forms!tblItems!Month1.Value = 0
            Forms!tblItems!Month2.Value = 0
            Forms!tblItems!Month3.Value = Forms!tblItems![Total Cost].Value
            Forms!tblItems!Month4.Value = 0
            Forms!tblItems!Month5.Value = 0
            Forms!tblItems!Month6.Value = 0
            Forms!tblItems!Month7.Value = 0
            Forms!tblItems!Month8.Value = 0
            Forms!tblItems!Month9.Value = 0
            Forms!tblItems!Month10.Value = 0
            Forms!tblItems!Month11.Value = 0
            Forms!tblItems!Month12.Value = 0

etc,etc...

end if