DB<1> sub param { return "zorch" }

  DB<2> $name = param( "name" )

  DB<3> $hash{ "name" } = "this and that" if $name ne "";

  DB<4> p $hash{ "name" }
this and that
[download]

Works fine. Something Else Is Wrong. perldoc perldebug, make sure that what values you think things have are what you think they are.