Untitled

PHP: Validating form and displaying alert
if($login != '')
{
$query = "Select LoginName from register where LoginName='".$login."'";
$result = mysql_query($query);
if($result)
{
?>
<script type="text/javascript">
alert("Login name exist");
</script>
<?php
}
else
{
insert into database
}
}

if( mysql_num_rows($result) > 0 )

<?php
if($login != ''){
  $query = "Select LoginName from register where LoginName='".$login."'";
  $result = mysql_query($query);
  if($result){
    if(mysql_num_rows($result) > 0) {
?>
        <!-- LoginName already exists, do something here -->
        <script type="text/javascript">
          alert("Login name exist");
        </script>
<?php
   }
   else {
     // LoginName avaialable
     // your logic for registering user goes here
   }
 }
 else
 {
   // query not executed, handle this issue properly
 }
}