Description
int 
checkdnsrr ( string host [, string type] )
     Searches DNS for records of type type
     corresponding to host. Returns TRUE if any
     records are found; returns FALSE if no records were found or if
     an error occurred.
    
     type may be any one of: A, MX, NS, SOA,
     PTR, CNAME, AAAA, A6, SRV, NAPTR or ANY.  The default is MX.
    
     host may either be the IP address in
     dotted-quad notation or the host name.
    
     
Note: 
       AAAA type added with PHP 5.0.0
      
     
Note: 
       This function is not implemented on Windows platforms. Try the
       PEAR class
       Net_DNS.
      
     See also dns_get_record(),
     getmxrr(),
     gethostbyaddr(),
     gethostbyname(),
     gethostbynamel(), and the named(8) manual
     page.