JavaScript check form Demo

There is two way to check form with JavaScript.
but here choses one them to demo.

1. prepare JavaScript function

<script language="javascript">
function checkForm()
{

 if(document.formaddNews.m_name.value=="")
 {
  alert("PLZ enter name!");
  document.formaddNews.m_name.focus();
  return false;
 }
 if(document.formaddNews.m_content.value=="")
 {
  alert("PLZ enter product content!");
  document.formaddNews.m_content.focus();
  return false;
 }
 if(document.formaddNews.m_type.value=="")
 {
  alert("PLZ enter product type!");
  document.formaddNews.m_type.focus();
  return false;
 }

 return confirm('R U sure?');
}

2.HTML

<form action="" enctype="multipart/form-data" method="POST" name="formaddNews" id="formaddNews" onSubmit="return checkForm();">

<input type="submit" name="Submit2" value="add">