upgrading jscript to work with CRM 2013 (from CRM 2011 online) question

I have few web-resource written in CRM 2011 online and it seems some of jscripts may not work with CRM 2013.  How could we upgrade the scritpt or find the correct methods to use. Appreciate your help.  It seems the following may not work - the ones italized as below:

 crmForm.all.address1_postalcode.DataValue;

Xrm.Page.getAttribute("new_source").getSelectedOption().text;

 accountLookup.DefaultValue[0].data = accountLookup.getValue()[0].data;