How do I: Set the ID attribute of a table row using jQuery and SharePoint Designer
While customizing an “add new item” form, you might find yourself needing to manipulate form elements via jQuery. However, before you can do that you must and an #id or .class to the elements in question. I will be adding an #id in this demonstration. But why would I want to manipulate form elements in the first place? If you wanted to hide/show a textbox based on the user selection of a checkbox you could use this technique.
How do I: Implement $().SPServices.SPLookupAddNew
Using jQuery to hide/show form elements based on checkbox value
How can I validate a textbox using the PreSaveAction()
How do I: Create a simple form to collect data in SharePoint 2010
How can I hide/show a textbox based on a radio button selection?
How can I hide/show a textbox based on a drop-down value?