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POHow to make an AJAX call wait for a server side response?
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copied!<p>These are my files : </p> <p><strong>index.html</strong></p> <pre><code><form action="#" method="POST"> <label for="Username">Username :</label><br/> <input type="text" id="Username" name="username"/><span id="usr"></span><br/> <label for="Email">Email :</label><br/> <input type="text" id="Email" name="email"/><br/> <input type="submit" value="Register" id="submit"/> </form> </code></pre> <p><strong>userresponse.php</strong></p> <pre><code><?php require ("DBC.php"); $usern = $_POST["username"]; function isAvailable($str) { $sql= "SELECT username FROM mytable WHERE username = '$str'"; $result=mysql_query($sql)or die(); $count = mysql_num_rows($result); if($count>0) return true; else return false; } if (isAvailable($usern) == true) echo "false"; else echo "true"; ?> </code></pre> <p><strong>checkuser.js</strong></p> <pre><code>$(document).ready(function() { var usrn = $("#Username"); var usr = $("#usr"); usrn.blur(function(){ if(usrn.val()=="") { usr.html("Empty field"); return false; } else { var username = usrn.val(); usr.html('Cheking username...'); alert(username); $.ajax({ url: "userresponse.php", type: "POST", data: username, success: function (data) { if(data.val() == "true") { usr.html('Available username'); } else if(data.val() == "false") { usr.html('Username already taken'); } }}) return data.val(); } }); }); </code></pre> <p>I know that AJAX is asynchronous and doesn't wait for the response from the server but I want to know how to fix it and make this call wait for the response.</p>

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