<form id="demo">

<fieldset>

<label for="demo_input">Value to parse: <input type="text" id="demo_input"></label>

</fieldset>

<fieldset>

<input type="submit" id="demo_btn" value="Alert parsed number">

</fieldset>

</form>

<script>

YUI().use("node", "datatype-number", function (Y) {

Y.on("submit", function(e){

e.halt();

var input = Y.one("#demo_input").get("value"),

output = Y.DataType.Number.parse(input);

if(output === "") {

output += "(Invalid value)"

}

alert(output);

}, "#demo");

});

</script>