  We study the probability that all the eigenvalues of $n\times n$ Hermitian
matrices, from the Laguerre unitary ensemble with the weight
$x^{\gamma}\mathrm{e}^{-4nx},\;x\in[0,\infty),\;\gamma>-1$, lie in the interval
$[0,\alpha]$. By using previous results for finite $n$ obtained by the ladder
operator approach of orthogonal polynomials, we derive the large $n$
asymptotics of the largest eigenvalue distribution function with $\alpha$
ranging from 0 to the soft edge. In addition, at the soft edge, we compute the
constant conjectured by Tracy and Widom [Commun. Math. Phys. 159 (1994),
151-174], later proved by Deift, Its and Krasovsky [Commun. Math. Phys. 278
(2008), 643-678]. Our results are reduced to those of Deift et al. when
$\gamma=0$.
