[RESOLVED] php with javascript? check if username is taken

[Justa Lol]

i'm making a registration form and i want it to check if the username has been taken while the user is registering (before the user submits the form)

how to do this?

[I_Love_My_Vans]

Just a quick thought

1) On the onBlur event of the username field
2) Use xmlhttprequest to fire your username to a php script (e.g. 'http://domain.com/checkUsername.php?username'+element.value)
3) Using PHP, check the usernames status, return this value
4) Depending on the result output either a success of failure message

Sorry I cannot provide an example right now, but Googling these stages should sort you out, post back with any problems you may have.

[Justa Lol]

thats a good tip, i will do some searching and return here

[bharanidharanit]

Hi,
I recently made an registration form, and checks for the existing username using AJAX. Try this.

function exists_username(field)
{
	if (window.XMLHttpRequest) 
	{
	  	XMLHttpRequestObject = new XMLHttpRequest();
	}
	else if (window.ActiveXObject) 
	{
		XMLHttpRequestObject = new ActiveXObject("Microsoft.XMLHTTP");
	}
	field = field.value;
	var url = "functions.php?ud="+ field;
	if(XMLHttpRequestObject) 
    {
	  var obj = document.getElementById("v1");  //to display the error message as "Username already taken"
      XMLHttpRequestObject.open("GET", url,false); 
      XMLHttpRequestObject.onreadystatechange = function() 
      { 
        if (XMLHttpRequestObject.readyState == 4 && 
          XMLHttpRequestObject.status == 200) 
          { 
	        if(XMLHttpRequestObject.responseText=="Username Already Exists")  
	        {
				obj.innerHTML = XMLHttpRequestObject.responseText;
				return false;//but this is not returning as false. 				
			}
			return false;
          } 
      } 
      XMLHttpRequestObject.send(""); 
    }
}

functions.php

//connection to the host&database
$query = "SELECT username
			  FROM users
			  WHERE username='$ud';";
	$result = mysqli_query($dbconn,$query);
	if(mysqli_num_rows($result)>1)
	{echo "Username Already Exists";}

[kows]

I would personally advise you find a tutorial about ajax and use that instead of using any of the code posted above.

[Justa Lol]

yeah thats what i will do too, otherwise i won't learn much of it..

[visualAd]

I would personally advise you find a tutorial about ajax and use that instead of using any of the code posted above.

The code is also vulnerable to SQL injection; uses register globals and sends reduncdant information. Prehaps its best to delete the entire post.