thanks for your help but exactly what i want to make is to delete a certain zone from a file the zone will be provided
by the user input which i assigned at the start of my code
and then uses the $block variable to count the range of the curly brackets until the end of the zone
Example for what iam taking about

zone "foo.com" {
type master;
file path to file ;
};

zone "bar.com" {
type master;
file path to file ;
additional informations {
blah blah blab 
}
}

zone "perl.com" {
type master;
file path to file;
}
[download]

i want to delete lines from start of the the zone which is provided by targetdomain variable which is entered by the user
after the script is running assume that the targetdomain was = bar.com the output

 
zone "foo.com" {
type master;
file path to file ;
};

zone "perl.com" {
type master;
file path to file;
};
[download]

and thanks for your care