if(window.addEventListener) {
window.addEventListener("load", loadEvents, true);
}
else if(window.attachEvent) {
window.attachEvent("onload", loadEvents);
}

function loadEvents() {
numberinput = document.getElementById('numberinput');
numberinput.onkeypress = detectkey;
numberinput.focus();
document.getElementById('numberinputform').onsubmit = checkForm;
}

function detectkey(e) {
	if(!e) {
	e = window.event;	
	}
	if(e.keyCode) {
	code = e.keyCode;
	}
	else if(e.which) {
	code = e.which;
	}
	if(!code) {return true;}
	if(((code <= 57 || code >= 400) && !(code == 32 || (code >= 42 && code <= 47))) || e.ctrlKey) {
	return true;
	}
	else {
	return false;
	}
}

function checkForm() {
if(document.getElementById('numberinput').value == "") {return false;}
else {return true;}
}