Jquery returns NaN,any idea?

HTML code:

<form id="hostadd" action="addmoney.php?taskid=12" method="post" onSubmit="return false">
<input type="hidden" name="mode" value="" />
current unit price:$
<input id="unitprice" name="unitprice"  type="text" size="5" maxlength="6" value= 0.50 />&nbsp
Shortfall:<input id="shortfall" type="text"  name="shortfall" size="4开发者_运维技巧" maxlength="6" value=80 />
<input id="add_price" type="submit" value="Submit" onclick="Adjust()"/></form

Jquery code:

 function Adjust(){
        $totalprice=parseFloat($('unitprice').val())*parseInt($('shortfall').val());
          alert($totalprice);

        };

When I test

var unitPrice = $('#unitprice').val();
alert(unitPrice);
var shortFall = $('#shortfall').val();
alert(shortFall);

I got two blank alerts.

You're looking for an HTML 'shortfall' and 'unitprice':

<shortfall></shortfall>
<unitprice></unitprice>

Do you mean to do this? Maybe your after a class or ID selctor?

$('.unitprice').val() //class
$('#unitprice').val() //id
$('.shortfall').val() //class
$('#shortfall').val() //id

Try looking at each individual component to see which is failing.

alert($('#unitprice').val());
alert(parseFloat($('#unitprice').val()));
alert($('#shortfall').val());
alert(parseInt($('#shortfall').val(),10);

Also, pass the radix to parseInt() (note: below I assume you are wanting decimal, so use 10)

parseInt($('#shortfall').val(),10)

Although the default is 10, its dangerous not to stipulate it. If a zero left-padded number gets passed then praseInt assumes Octal.

alert(parseInt(010)); // alerts '8'
alert(parseInt(010),10); // alerts '10'

The jQuery $ function eats a CSS-like selector. So $('unitprice') looks for an element <unitprice />. But as you're working with HTML, there is no such thing!

What you mean to say is $('#unitprice'), referring to any element with the id unitprice.

Could you put alert there like this?

function Adjust(){
    alert([$('unitprice').val(),$('shortfall').val(),$('unitprice').val().length,$('shortfall').val().length]);
}

I believe one of the value might have non digits parts

You're most likely grabbing an invalid value. Check the contents of unitPrice and shortFall:

var unitPrice = $('unitprice').val();
alert(unitPrice);
var shortFall = $('shortfall').val();
alert(shortFall);

Most likely one of these will be empty or show an invalid number.