Function with arguments not working with window.onblur and onfocus in javascript

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Javascript

jQuery

The following code isn't working

Code:

window.onfocus = welcome("John Doe");
window.onblur = bye("John Doe");

function welcome(name) {
    $("p").append("Welcome back " +name+ " <br>");
}

function bye(name) {
    $("p").append("Good bye " +name+ " see you soon <br>");
}

However I noticed that this code works for custom functions that dont take any argument. See code below. The following code is working:

Code:

window.onfocus = welcome; //No Argument here so this code works
window.onblur = bye; //Same here... No argument for the function

function welcome(name) {
    $("p").append("Welcome back John Doe <br>");
}

function bye(name) {
    $("p").append("Good bye John Doe see you soon <br>");
}

I am new to jquery and javascript and this stuff is confusing me. Can someone please explain why exactly it isn't working. and how can I make a custom function with arguments work with window.onfocus and onblur method. (reason for working or not working is more important for me as I want to understand the mechanics rather than cramming up the snippets)

What I have tried:

window.onfocus = welcome("John Doe");
window.onblur = bye("John Doe");

function welcome(name) {
    $("p").append("Welcome back " +name+ " <br>");
}

function bye(name) {
    $("p").append("Good bye " +name+ " see you soon <br>");
}