Study of e^{+}e^{-} --> \tilde{\chi}^{+}_{1} \tilde{\chi}^{-}_{1} --> \tilde{\tau}^{+}_{1}\nu_{\tau} + \tilde{\tau}^{-}_{1}\bar{\nu}_{\tau}

In Supersymmetry with large $\tan \beta$ values, the lighter stau (${\tilde{\tau }}_1$) may be lighter than the lightest chargino (${\tilde{\chi }}_1^{\pm }$). The decay $\tilde{\chi}^{\pm}{1} \to \tilde{\tau}^{\pm}{1} \nu_{\tau}$,followedby$\tilde{\tau}^{\pm}{1} \to \tilde{\chi}^{0}{1} \tau$, alters a phenomenology of the chargino production. We study the chargino pair production at future $e^{+}{e}^{-}$ linear colliders.