Let $\displaystyle (f_t)_{t \geq 0}$ be a deterministic process (i.e. independent of $\displaystyle \omega$) such that $\displaystyle \int_{0}^{\infty }\int_{t}^{2}dt<\infty$. Then this process obviously belongs to $\displaystyle H$. Show that for each t the integral $\displaystyle \int_{0}^{t}f_sdW_s$ is a normal random variable with mean 0 and variance $\displaystyle \int_{0}^{t}f_s^2ds$

Any help?

Thanks