Ttdfjt

I want to override js function on shipping method section :
i checked on inspect Element below is the function is calling on click on continue
button Can you please help me to find out where i can get that function

onclick="shippingMethod.save()




<checkout_onepage_index>
 <reference name="head">
 <action method="addItem"><type>skin_js</type><name>js/custom.js</name></action>
 </reference>
 </checkout_onepage_index>

path : skinfrontendpackagethemejscustom.js

// shipping method
var ShippingMethod = Class.create();
ShippingMethod.prototype = 
 initialize: function(form, saveUrl)
 this.form = form;
 if ($(this.form)) 
 $(this.form).observe('submit', function(event)this.save();Event.stop(event);.bind(this));
 
 this.saveUrl = saveUrl;
 this.validator = new Validation(this.form);
 this.onSave = this.nextStep.bindAsEventListener(this);
 this.onComplete = this.resetLoadWaiting.bindAsEventListener(this);
 ,

 validate: function() 
 var methods = document.getElementsByName('shipping_method');
 if (methods.length==0) 
 alert(Translator.translate('Your order cannot be completed at this time as there is no shipping methods available for it. Please make necessary changes in your shipping address.').stripTags());
 return false;
 

 if(!this.validator.validate()) 
 return false;
 

 for (var i=0; i<methods.length; i++) 
 if (methods[i].checked) 
 return true;
 
 
 alert(Translator.translate('Please specify shipping method.').stripTags());
 return false;
 ,

 save: function()
alert('tttttttttttttttttttt');
 if (checkout.loadWaiting!=false) return;
 if (this.validate()) 
 checkout.setLoadWaiting('shipping-method');
 var request = new Ajax.Request(
 this.saveUrl,
 
 method:'post',
 onComplete: this.onComplete,
 onSuccess: this.onSave,
 onFailure: checkout.ajaxFailure.bind(checkout),
 parameters: Form.serialize(this.form)
 
 );
 
 ,

 resetLoadWaiting: function(transport)
 checkout.setLoadWaiting(false);
 ,

 nextStep: function(transport)
 if (transport && transport.responseText)
 try
 response = eval('(' + transport.responseText + ')');
 
 catch (e) 
 response = ;
 
 

 if (response.error) 
 alert(response.message);
 return false;
 

 if (response.update_section) 
 $('checkout-'+response.update_section.name+'-load').update(response.update_section.html);
 

 payment.initWhatIsCvvListeners();

 if (response.goto_section) 
 checkout.gotoSection(response.goto_section, true);
 checkout.reloadProgressBlock();
 return;
 

 if (response.payment_methods_html) 
 $('checkout-payment-method-load').update(response.payment_methods_html);
 

 checkout.setShippingMethod();
 

Can you please help me to find out the exact location & file name

shippingMethod is created in app/design/frontend/base/default/template/checkout/onepage/shipping_method.phtml

class ShippingMethid is in skin/frontend/base/default/js/opcheckout.js
somewhere at 591 line.

And this is how you can override JS methods:
https://stackoverflow.com/questions/13379034/how-to-override-product-js-file-in-magento

This also works: https://stackoverflow.com/questions/11941257/overriding-extending-the-magento-core-javascript-files

skin/frontend/package/theme/js/opcheckout.js //shipping method