build_url(account => "test",transaction => "test1", location => "India", fname => "Nikhil", lname => "jain"); 

build_url(account => "test", fname => "nikhil", lname => "jain"); 

build_url(account => "test" ,transaction => "test1", fname =>"nikhil", lname => "jain"); 


 
sub build_url {
my (%args) = @_;
my $fname = $args{fname} || "Bob the Builder";
my $lname = $args{lname} || "none that we know";

}