vb post 密码格式出错,求指点

Function HttpPost(Url As String, PostMsg As String) As String
 '自己写的发送Post的函数
 '函数返回值是获得的返回信息(HTML)
 '第一个参数是要发送的Url地址
 '第二个参数是要发送的消息(键值对应，不必编码)
 Dim XmlHttp As Object
 Set XmlHttp = CreateObject("Msxml2.XMLHTTP")
 If Not IsObject(XmlHttp) Then
 Set XmlHttp = CreateObject("Microsoft.XMLHTTP")
 If Not IsObject(XmlHttp) Then Exit Function
 End If
 XmlHttp.Open "POST", Url, False
 XmlHttp.setRequestHeader "CONTENT-TYPE", "application/x-www-form-urlencoded"
 XmlHttp.Send EnUrl(PostMsg)
 Do While XmlHttp.readyState <> 4
 DoEvents
 Loop
 '如果把下面一行(以及后面的End IF)的注释去除，即设置为仅当返回码是200时才返回页面内容
 'If XmlHttp.Status = 200 Then
 HttpPost = XmlHttp.responseText
 'End If
End Function

Function EnUrl(Str)
 EnUrl = ""
 For i = 1 To Len(Str)
 ThisChr = Mid(Str, i, 1)
 If Abs(Asc(ThisChr)) < &HFF Then
 EnUrl = EnUrl & ThisChr
 Else
 innerCode = Asc(ThisChr)
 If innerCode < 0 Then
 innerCode = innerCode + &H10000
 End If
 Hight8 = (innerCode And &HFF00) \ &HFF
 Low8 = innerCode And &HFF
 EnUrl = EnUrl & "%" & Hex(Hight8) & "%" & Hex(Low8)
 End If
 Next
End Function

Private Sub Command1_Click()
UserNameVal = Text1.Text
UserPwdVal = Text2.Text
UserPwd2Val = Text2.Text
IdCardVal = Text3.Text
RealNameVal = Text4.Text
MsgBox HttpPost("http://www., "UserName:UserNameVal,UserPwd:UserPwdVal,UserPwd2:UserPwd2Val,IdCard:IdCardVal,RealName:RealNameVal")
End Sub
vb post 密码格式出错,求指点