beginner plot function with parameter

*To*: mathgroup at smc.vnet.net*Subject*: [mg74021] beginner plot function with parameter*From*: "Wei Li" <wei_li92 at hotmail.com>*Date*: Tue, 6 Mar 2007 05:30:56 -0500 (EST)

Dear Mathgroup, I am using mathematica 5 to plot a function with some parameter, I want to plot for example a simple parabolic function with positive parameter s: f[z_]:=(z/s)^2; Plot[f[z],{z,-s,s}]; mathematica code doesn't seem to work, anyone can help? Thanks! Wei