iframe with localhost:port/mysql not displaying page

iframe with localhost:port/mysql not displaying page

I would like to display in iframe on my web page phpmyadmin....when i
enter in chrome: http://xxx.xxx.x.xx:81/mysql it loads phpmyadmin just
fine. when i add iframe that address it does not display. so i figureout
that if i add in iframe http://xxx.xxx.x.xx:81/ it opens server main page
not phpmyadmin...so problem is that iframe cannon display web page if
after port is /mysql.
How to fix this problem that iframe accept full http address? Is
alternative html code to iframe or someone have solution how to fix this?
Many Thanks.