[jQuery] How would I write this CF in JS?

[Rick Faircloth]

Hi, all...

I want to create custom validation that would
test input the same as this ColdFusion function,

<CFIF Not IsNumeric(REReplace(Form.Principal, "[$.,]", "", "All"))>

which states that "if after all dollar signs, commas, and periods
are stripped from the input value, the value is not numeric..."

How would I write that in Javascript so I can use it as a custom validation
in Jorn's Validation plug-in?

Realize that I don't want to change the value, I just want to run it through
a test...

CF-coders?

Thanks,

Rick