Why is the PNG Image transparent in IE6?

Png-8 mode of the image, if there is no gradient is transparent, if there is a gradient is not transparent. JS support is required.

 

  Function  Correctpng ()  //  Correctly handle PNG transparency in win IE 5.5 & 6.  
  {
  VaR  Arversion  =  Navigator. appversion. Split (  "  MSIE "  )
  VaR  Version  =  Parsefloat (arversion [  1  ])
  If  (Version  > =     5.5  )  &&  (Document. Body. filters )){
  For (  VaR  J  =     0  ; J  <  Document. Images. length; j  ++  ){
  VaR  IMG  =  Document. Images [J]
  VaR  Imgname =  IMG. SRC. touppercase ()
  If  (Imgname. substring (imgname. Length  -     3  , Imgname. length)  =     "  PNG  "  ){
  VaR  Imgid  = (IMG. ID)  ?     "  Id ='  "     +  IMG. ID  +     "  '  "  :  ""  
  VaR Imgclass  =  (IMG. classname)  ?     "  Class ='  "     +  IMG. classname  +     "  '  "  :  "" 
  VaR  Imgtitle  =  (IMG. Title)  ?     "  Title ='  "     +  IMG. Title  +     "  '  " :  "  Title ='  "     +  IMG. ALT  +     "  '  "  
  VaR  Imgstyle  =     " Display: inline-block;  "     +  Img.style.css text
  If  (IMG. Align  =     "  Left  "  ) Imgstyle  =     "  Float: left; "     +  Imgstyle
  If  (IMG. Align  =     "  Right  "  ) Imgstyle  =     "  Float: right;  "    +  Imgstyle
  If  (IMG. parentelement. href) imgstyle  =     "  Cursor: hand;  "     +  Imgstyle
  VaR  Strnewhtml  =     " <Span  "     +  Imgid  +  Imgclass  +  Imgtitle
  +     "  Style = \  ""  +  "  Width:  " + IMG. Width +  "  Px; height:  "  + IMG. height +  "  Px;  "  + Imgstyle +  "  ;  "  
+  "  Filter: progid: DXImageTransform. Microsoft. alphaimageloader  " 
+  "  (SRC  =  \  '  "+ IMG. SRC + "\  '  , Sizingmethod  =  '  Scale  '  );\  "  > </Span>  " 
IMG. outerhtml  =  Strnewhtml
J  =  J  -     1  
}
}
}
}
Window. attachevent (  "  Onload  "  , Correctpng );