  We report a measurement of the charge asymmetry for same-sign dileptons in
$B^0$-$\bar{B}^0$ mixing, $A_{\rm sl}$. The data were collected with the Belle
detector at KEKB. Using a data sample of 78 fb$^{-1}$ recorded at the
$\Upsilon(4S)$ resonance and 9 fb$^{-1}$ recorded at an energy 60 MeV below the
resonance, we measure $A_{\rm sl} = (-1.1 \pm 7.9(\text{stat}) \pm
7.0(\text{sys}))\times 10^{-3}$.
