Question

I have very simple code and I am not sure why the Foo function is not fired when the mouse is over the image:

here <img id="sss" alt="some image" onmouseover="Foo(this);" src="https://www.google.com/intl/en_com/images/srpr/logo3w.png" width="16" height="16"   />

<div onmouseover="Foo(this);"> 
    THIS IS DIV
</div>

function Foo(obj) 
{
    alert('s');
}

UPDATE 1:

What actually happens is that I create the image element dynamically and then add it to the page. The Foo function is already inside the JS file but it never gets called.

Answer 1

The code you have currently is correct, as this fiddle shows. I’m guessing your problem is that Foo is not global on your page.

---

Also, instead of passing this as a parameter to your function, you can set it as the this value inside of your function by using call

onmouseover="Foo.call(this);"

function Foo()  {
    alert(this.src); //this is the img you just mouse-overed 
}

---

Finally, consider changing Foo to foo, since functions starting with capital letters usually denote constructors in JavaScript.