<html><script>//<!--function foo(){ document.getElementById('me').setAttribute('onmouseover',"alert('test')")}function bar(){ var script = document.createElement('script'); script.innerHTML = 'alert(1337)'; script.type = 'text/javascript'; var head = document.getElementsByTagName('head').item(0); head.appendChild(script);}//--></script><input type="button" value="click me" onclick="foo()" /><div id="me">I'm a div tag</div><hr /><input type="button" value="click me" onclick="bar()" /><div id="me2">I'm a div tag</div><hr /></html>