jstat - Calculating the inverse of the beta cumulative probability density in JavaScript -

i need duplicate functionality of excel function in javascript - inverse of beta cumulative probability density http://office.microsoft.com/en-gb/excel-help/beta-inv-function-hp010335670.aspx.

is there js library offers this? i've tried jstat (http://www.jstat.org/) not appear have particular calculation.

i've solved building more date version of jstat library here: https://github.com/jstat/jstat