Having Trouble With Event Listener: Detect Iframe Close Event Fromparent

I have an iframe that includes a button:
<input type="button" value="close this window" onclick="window.close();" >

I would like to detect the iframe close event from the parent window, I
was using this code but I did something wrong because the temp function
is fired every time the parent page loads:

function temp(){
alert('the iframe was closed');
}
function setup(){
var myIFrame = document.getElementById("iframe1");
if (myIFrame.addEventListener) {
myIFrame.addEventListener('onclose', temp(), false);
}else if (myIFrame.attachEvent) {
myIFrame.attachEvent ('onclose',temp);
}else{
myIFrame.onclose=temp();
}
}
window.onload=setup;