Dim str As String = "123"
str = iif(str > "", str & vbcrlf, str)
Dim str1 As string = ""
str1 = iif(str1 > "", str1 & vbcrlf, str1)
Dim str2 As string = "456"
str2 = iif(str2 > "", str2 & vbcrlf, str2)
msgbox(str & str1 & str2)