You need to place error messages in the DOM and show and hide them when appropriate.You want to react to more than just a submit event, like keyup and blur.You have used the element named above in your document, but the document type you are using does not define an element of that name.This error is often caused by: incorrect use of the "Strict" document type with a document that uses frames (e.g.For details, see the Script and Style elements section of the XHTML 1.0 Recommendation as well as the HTML compatibility guideline for embedded scripts.
Markup validation is an important step towards ensuring the technical quality of web pages.
The script has a catalog of almost all the common validation types built-in.
The idea is to create a set of “validation descriptors” associated with each element in a form.
First, download the Java Script form validation script here.