I'm trying to call the webmethod fucntionality using AJAX but unable to get the appropriate results. I have googled my problem and found many solution but those didn't worked for me. Please guide me what I'm doing wrong. Help will be appreciated.

Cheers

Code Snippet

 function checkUserNameExists() {



//initialization

var pagePath = window.location.pathname + /getUsername;

var value = document.getElementById('control_userName').value;

var dataString = { 'value':' + value + ' };

$.ajax({

    type: GET,

    url: pagePath,

    data: dataString,

    contentType: application/json; charset=utf-8,

    dataType: json,

    error:

            function (XMLHttpRequest, textStatus, errorThrown) {



            },

    success:

            function (result) {

                var flag = true;

                if (result != null) {

                    flag = result.d;

                    if (flag == True) {

                        alert('okay fine you are good');

                    }

                    else {

                        alert('try again');

                    }

                }

            }

});

 }

Method in Behind Code file

    [WebMethod]

    [ScriptMethod(UseHttpGet = true)]

    public string getUsername(string value)

    {

        return True;

    }

EXCEPTION

 ExceptionType: System.InvalidOperationException

  Message: An attempt was made to call the method 'getUsername' using a        POST request, which is not allowed.