Help with functional integral

Question

I'm stuck on how to do a functional integral. The integration I'm trying to do is of this form $\frac{\partial}{\partial B(\tau)} \left[ \exp\left(-B^2(\tau)\right)+\int_{0}^{\tau} \phi\left(\ln\left(\frac{B(\tau)}{B(u)}\right)\right)du + \int_{0}^{\tau} \Phi\left(\ln\left(\frac{B(\tau)}{B(u)}\right)\right)du \right]$ where $B()$ is an arbitrary (but continuous and otherwise well behaved) function, $\Phi()$ is the cumulative normal density, $\phi()$ is the normal density and $\ln$ is the natural logarithm