Validation of name fields using javascipt

The following code can be used for validating name like fields.(Useful when dealing with html forms)

This code uses two built in functions

1)charAt()

2) indexOf()

charAt()- Returns the character at the specified index in a string.

Ex: charAt(5)-->  character at 6th position(Starting with 0)

indexOf() - Returns the position of the first occurrence of a specified value in a string and return -1  if  not found.

Bellow code has a variable not_needed. You can simply specify the unwanted character inside the double quotes.

<script type="text/javascript">

function validate()
{
var not_needed = "!@#$%^&*()+=-[]\\\';,./{}|\":<>? 1234567890";


if(document.myform.name1.value =="")
{
alert("Invalid name");
return false;
}

for (var i = 0; i < document.myform.name1.value.length; i++)
{
  if (not_needed.indexOf(document.myform.name1.value.charAt(i)) != -1)
 {
  alert ("Invalid name");
  return false;
  }
}

}

</script>

Form

<form action="sample.php" name="myform" method="post" onsubmit="return validate()">

Name:  <input type="TEXT" name="name1">

Posted in: charAt,charAt(),form validation,forms,html,html forms,indexOf,indexOf(),javascript,javascript form validation,php,tricks,validation