Basic Form Validation

March 13th, 2009 | Author: Haider al-Khateeb

Who doesnt need to implement a data validation technique along with every online form?

Bellow is a basic javascript code to check that no form is submitted with empty fields:

<html>
<head>
<script Language="JavaScript"><!--
function Validator(Form)
{
 
  if (Form.UserName.value == "")
  {
    alert("Please enter a value for the \"User Name\" field.");
    Form.UserName.focus();
    return (false);
  }
 
  if (Form.Password.value == "")
  {
    alert("Please enter a value for the \"Password\" field.");
    Form.Password.focus();
    return (false);
  }
 
  if (Form.FullName.value == "")
  {
    alert("Please enter a value for the \"Full Name\" field.");
    Form.FullName.focus();
    return (false);
  }
  return (true);
}
//--></script>
</head>
 
<body>
<center>
<form name="Signup" action = "submit_form.php" method = "post" 
onsubmit="return Validator(this)" >
Username: <input type ="text"  name="UserName" size="20"> <b>-</b> 
Password: <input type ="text"  name="Password" size="20"> <b>-</b> 
Fullname: <input type ="text"  name="FullName" size="20"> <b>-</b> 
<input name="Submit" type="submit" value="Submit">
</form>
</center>
</body>
</html>