Save or Download Javascript String as a file

I have an HTML str开发者_StackOverflowing in javascript variable. I have to save/Download the string as a file on link click. It should be cross browser compatible.

I thought window.open with attachment Content-Disposition header, but not good solution because popup may be blocked.

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As mentioned here, you could use downloadify: https://github.com/dcneiner/Downloadify. The client will need flash though.