In such cases Infopath is the best one to validate based on the rules. Any way you don't want to implement in infopath right!! So, here i am giving my idea. I am not guaranteed that it is the final solution.
1. You have to approach through the application pages by creating the in visual studio. In your example credit card application, you can put all these fields into one application page and add the required javascript, jquery scripts and you can perform well.
2. Otherwise if you want to display only few fields, you can write the entire script in javascript or jquery and give a link to the content editor webpart. I posted in my blog similar kind of thing. Visit
this. This is not equally same. i am just showing how to use the jquery/javascript in content editor webpart. You have to customize as per your requirement.
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