春天在哪里舞蹈教学版:VB小问题

想问下,下边程序中的ST1~5是哪来的啊 其他代码中都没提到过
Private Sub FuncChangeAddr(ByVal st1 As String, ByVal st2 As String, ByVal st3 As String, ByVal st4 As String, ByVal st5 As String)
Dim strAddr As String
Dim ilen As Long
strAddr = st1 & st2 & st3 & st4 & st5
ilen = Len(strAddr)
Select Case ilen
Case 0:
TxtSend.Text = "01"
Case 2:
TxtSend.Text = "03" & " " & strAddr
Case 4:
TxtSend.Text = "04" & " " & Mid(strAddr, 1, 2) & " " & Mid(strAddr, 3, 2)
Case 6:
TxtSend.Text = "05" & " " & Mid(strAddr, 1, 2) & " " & Mid(strAddr, 3, 2) & " " & Mid(strAddr, 5, 2)
Case 8:
TxtSend.Text = "06" & " " & Mid(strAddr, 1, 2) & " " & Mid(strAddr, 3, 2) & " " & Mid(strAddr, 5, 2) & " " & Mid(strAddr, 7, 2)
Case 10:
TxtSend.Text = "07" & " " & Mid(strAddr, 1, 2) & " " & Mid(strAddr, 3, 2) & " " & Mid(strAddr, 5, 2) & " " & Mid(strAddr, 7, 2) & " " & Mid(strAddr, 9, 2)
End Select
接口?那他是怎么取值的呢~strAddr是有ST1~5组成,但是没看到有给他们取值啊~! 汗~ 不明白