I need to get a value from another page. But I get this error with the following code. How can I fix it?
$(document).ready(function() { $("[name='submit']").click(function() { $.ajax({ type: "POST", data: $(".form-signup").serialize(), url: "external.asp", success: function(output) { alert(output.getResponseHeader("Content-Length")); }, error: function(output) { $('.sysMsg').html(output); } }); }); }); First, your settings object is not well formed, the success function is not terminated.
Edit: Seems that you are using jQuery 1.3.x, if so, the $.ajax function itself returns the XHR object:
$(document).ready(function() { $("[name='submit']").click(function() { var xhr = $.ajax({ type: "POST", data: $(".form-signup").serialize(), url: "external.asp", success: function(output, status) { alert(xhr.getResponseHeader("Content-Length")); }, error: function(output) { $('.sysMsg').html(output); } }); }); }); For jQuery 1.4+ versions:
Then, when the success callback its executed three arguments are passed (success(data, textStatus, XMLHttpRequest)), you need to call the getResponseHeader on the XmlHttpRequest object, the third argument:
$(document).ready(function() { $("[name='submit']").click(function() { $.ajax({ type: "POST", data: $(".form-signup").serialize(), url: "external.asp", success: function(output, status, xhr) { alert(xhr.getResponseHeader("Content-Length")); }, error: function(output) { $('.sysMsg').html(output); } }); }); }); 
Is it a cross-domain call? You may be entering a whole new world of pain? (Cross Domain Resource Sharing GET: 'refused to get unsafe header "etag"' from Response) when you do that.
