Default fonts for browser comes down to which font is the default for the system.
If you are referring to the standard Font Face HTML types they are:
font face="Arial, Helvetica, sans-serif"
font face="Times New Roman, Times, serif"
font face="Courier New, Courier, mono"
font face="Georgia, Times New Roman, Times, serif"
font face="Verdana, Arial, Helvetica, sans-serif"
font face="Geneva, Arial, Helvetica, san-serif"
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me Flash questions, that's what the Forums are for!
Please don't rely on me reading my PMs either. Email me about important stuff.