如何用VB在图像上弄一些透明flash?

下面这个是把2个图片混合的，你研究一下就知道怎么弄了。
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模块里：
Public Type rBlendProps
tBlendOp As Byte
tBlendOptions As Byte
tBlendAmount As Byte
tAlphaType As Byte
End Type

Public Declare Function AlphaBlend Lib "msimg32" (ByVal hDestDC As Long, _
ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, _
ByVal nHeight As Long, ByVal hSrcDC As Long, _
ByVal xSrc As Long, ByVal ySrc As Long, ByVal widthSrc As Long, _
ByVal heightSrc As Long, ByVal blendFunct As Long) As Boolean

Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
(Destination As Any, Source As Any, ByVal Length As Long)

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form1里：
Dim lTime As Byte

Sub ShowTransparency(cSrc As PictureBox, cDest As PictureBox, _
ByVal nLevel As Byte)
Dim LrProps As rBlendProps
Dim LnBlendPtr As