#define the sub
sub strip_space
{
    # get our parameter
    my $val = $_[0];

    # if not given a reference, return false
    return false if ref($val) ne "SCALAR";

    # remove whitespace and retrn true on success
    $$val =~ s/\s+//g;
    return 1;
}

# and call said sub
$test = "this will have no spaces!";
print $test if strip_space($test);
print $test if strip_space(\$test);