How do you prepare ethyl cyanide and ethyl isocyanide from a common alkyl halide.

Alkyl halide reacts with alcoholic KCN forms alkyl cyanide as a major product while with alcoholic AgCN gives alkyl Iso cyanide as a major product
${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl}+\underset{\left(\mathrm{alc}\right)}{\mathrm{KCN}}\to \underset{\left(\mathrm{major}\right)}{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{CN}}+\underset{\left(\mathrm{minor}\right)}{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{NC}}$
${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl}+\underset{\left(\mathrm{alc}\right)}{\mathrm{AgCN}}\to \underset{\left(\mathrm{major}\right)}{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{NC}}+\underset{\left(\mathrm{minor}\right)}{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{CN}}$