What is difference between .htc and .js file?

W开发者_StackOverflowhat is difference between .htc and .js file? Can we convert any .htc file to a .js file?

The problem is if we use htc to make png fixes, then we add htc to css file using

body { behavior: url("csshover3.htc"); } 

But this is not W3C valid, so want to convert the .htc to .js and then use as a js file to attach in so it will be W3C valid.

Can anyone tell me how to convert and use any .htc file as JavaScript file?

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From the Microsoft HTC Reference