Well, I see syntax errors in your code.
When you compare the text in the ComboBox you must put "Trinidad and Tobago" enclosed with "
MessageBox.Show ("Please ensure that countries are different.", "My Application", MessageBoxButtons.OK, MessageBoxIcon.Warning, MessageBoxDefaultButton.Button1) = DialogResult.OK
You cannot assign a value (DialogResult.OK) to the MessageBox function. Beeing a function, it returns a value, which maybe DialogResult.OK.
To add items in the ComboBox cmbMonth, you must use something like this:
cmbMonth.Items.Add(January)
cmbMonth.Items.Add(February)
' etc...
You cannot compare a String variable (cmbMonth.Text) with a Date variable (January, February, etc.) like you are doing here:
If cmbMonth.Text = January Then
lblRate.Text = USagainstTT(4)
Else
End If
I think you must code something like this:
With cmbMonth
.Items.Add("January")
.Items.Add("February")
' etc...
End With
' ...
If cmbMonth.Text = "January" Then
lblRate.Text = USagainstTT(4)
End If
' etc...
Hope it helps