Comma in AS_HELP_STRING string

[jds.2005]

Hi;

I'd like to have a comma in my help string as follows:

AS_HELP_STRING([--with-wx=opt1,opt2], [specify 2 options separated by comma])

However the comma in '[--with-wx=opt1,opt2]' appears to be interpreted as the 
comma between the arguments rather than a character in the 1st string.  I get 
an error message when running autoconf:

Bad expression in eval (bad input): 31 > opt2

How can I embed a comma in the string?

Thanks very much,
Jerry