How would I create this these three functions for .php in and HTML webpage

similar to the examples. Function sayHi . This function should display a message to the user reading: "Hi [user], what can I do for you?" Where (user] will be filled in with the parameter found in $ GETI 'myName'] --) localhost: You are using function: sayHi Hi Nick, What can I do for you? If myName is null, display an error message. . Challenge You are using function: say Hi Hi, How about you give me your name? Note: .If you look at the URL bar you can see I am passing parameters using the "?" such as: .If I want to pass multiple parameters, I can use the "&" to append them such as: .These parameters will all show up in the super global array called $_GET. o index.php?myFunctiona sayH o index.php?myFunctiona sayH&myName-Nick