while($phone =~ /D/ || $len !=10){
 print "Please enter your 10 digit phone number:";
 $phone = <STDIN>;
 chomp($phone);
 #Find out the length of the string
 $len=($phone=~tr/[0-9]/[0-9]/);
}

#stor in $1 $2 $3 and format for international phone format

$phone=~/ddd)(ddd)(dddd)/;
$formattedphone="+"."1"." ".$1." ".$2." ".$3;