IE8中的对象预期的JScript错误

Question

Mostly dis can be possibly duplicate. But I dont know why I get this error. My Script code .

    $(document).ready(function () {        
            $(function () {
                $('input[name=Quantity]').blur(allownumbers);
            });

           function allownumbers() {
            alert('ad');
            var elements = document.getElementsByName('Quantity');
            alert(elements);
            for (var i = 0; i < elements.length; i++) {  
            if (elements[i].value == '' || elements[i].value < 1) {
                alert('Please enter a valid value');                    
                return false;
            }
            else if (elements[i].value > 100) {
                alert('Please enter a value less than 100');                
                return false;
            }
            }               
            return true;            
            }​
    });

My page code :

   <input id="Quantity" type="text" class="TxtBox" name="Quantity" value="@item.Quantity" onblur="return allownumbers()" maxlength="3"/> 

And the script references which I have was

<script src="~/Scripts/jquery-1.7.1.min.js" type="text/javascript"></script>  
<script src="~/Scripts/jquery.validate.min.js" type="text/javascript"></script>
<script src="~/Scripts/jquery.validate.unobtrusive.min.js" type="text/javascript">

What's wrong with my code. Any suggestions .. EDIT :

The function is not even called when I dont call it in the textbox.

Answer 1

You have duplicated your script references. You need only include each script once (preferrably the minified version unless it is a script you are actively debugging and writing). Secondly your initialization routine needs some help.

$(document).ready(function () {        
        $('input[name=Quantity]').blur(allownumbers);
});

function allownumbers() {
        alert('ad');
        var elements = document.getElementsByName('Quantity');
        alert(elements);
        for (var i = 0; i < elements.length; i++) {  
        if (elements[i].value == '' || elements[i].value < 1) {
            alert('Please enter a valid value');                    
            return false;
        }
        else if (elements[i].value > 100) {
            alert('Please enter a value less than 100');                
            return false;
        }
        }               
        return true;            
        }​

Now then, the allownumbers does not have to be outside of the original block, but for me it helps keep my scope clean. Secondly, $(document).ready ensures that your document is ready for use, so $(function () {}) is not necessary for JQuery call.

So eliminate duplicate script references, and you should be good.

Answer 2

Your allownumbers function doesn't exist at global scope (it's nicely contained within your outermost ready handler, which is good; the global scope is polluted enough already), but that's where the old-style DOM0 handler hooked up via the onblur="..." attribute on your Quantity field's markup is looking for it. That's why when the field blurs, you get that error.

Since you're already hooking it up correctly via jQuery later (in your inner ready handler), just remove the onblur attribute entirely from the field markup.

Other notes:

• You're using ready twice: First explicitly, then again inside that callback implicitly by passing a function reference into $ , which is a shorthand form of the same thing. You can remove the inner one, it's not doing anything other than calling the function inside it.

• You're loading both the unminified and minified scripts. Pick one set, not both.