Error changing the ports in Mamp

When i try to change the port , the error is show up “There is a problem with the server ports. Each server must be assigned a unique port. Please check your configuration.”

 

Finally , I was able to set port 3306 for SQL in the MAMP interface, and able to set port 80 for apache by editing the httpd.conf and changing 8888 to 80 on lines 48 and 182 , and it works.