Browser: hold "Alt" key focus on input text

Question

When user is typing in a html input text, is it possible to keep the browser from showing its menu when the user press the Alt key deliberately or by mistake

Answer 1

here is @Runtis code modified just changed e.keyIdentifier == "Alt" to 18==e.keyCode
http://jsfiddle.net/2dqCD/13/

document.addEventListener("keyup",function(e){    
    if(18 == e.keyCode && e.target.nodeName == "INPUT"){ 
        e.preventDefault ? e.preventDefault() : (e.returnValue=false)
    }
});