Why does an onclick property set with setAttribute fail to work in IE?

to make this work in both FF and IE you must write both ways:

    button_element.setAttribute('onclick','doSomething();'); // for FF
    button_element.onclick = function() {doSomething();}; // for IE

thanks to this post.

UPDATE: This is to demonstrate that sometimes it is necessary to use setAttribute! This method works if you need to take the original onclick attribute from the HTML and add it to the onclick event, so that it doesn't get overridden:

// get old onclick attribute
var onclick = button_element.getAttribute("onclick");  

// if onclick is not a function, it's not IE7, so use setAttribute
if(typeof(onclick) != "function") { 
    button_element.setAttribute('onclick','doSomething();' + onclick); // for FF,IE8,Chrome

// if onclick is a function, use the IE7 method and call onclick() in the anonymous function
} else {
    button_element.onclick = function() { 
        doSomething();
        onclick();
    }; // for IE7
}

works great!

using both ways seem to be unnecessary now:

execBtn.onclick = function() { runCommand() };

apparently works in every current browser.

tested in current Firefox, IE, Safari, Opera, Chrome on Windows; Firefox and Epiphany on Ubuntu; not tested on Mac or mobile systems.

• Craig: I'd try "document.getElementById(ID).type='password';
• Has anyone checked the "AddEventListener" approach with different engines?

There is a LARGE collection of attributes you can't set in IE using .setAttribute() which includes every inline event handler.

See here for details:

http://webbugtrack.blogspot.com/2007/08/bug-242-setattribute-doesnt-always-work.html