问jquery用于检查数据库中电子邮件的可用性/重复

EN

    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.0/jquery.min.js"></script>

<script type="text/javascript">

    $(document).ready(function () {

        $("#<%=txtEmailAddress.UniqueID%>").change(function () {

            var uname = $("#<%=txtEmailAddress.UniqueID%>");

            var msgbox = $("#status");

            if (Email.val().length > 0) {

                $.ajax({

                    type: "POST",

                    url: "SignUp.aspx/usp_CheckEmail",

                    data: "{'args': '" + Email.val() + "'}",

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

                    dataType: "json",

                    success: function (msg) {

                        if (msg.d == 'Available') {

                            Email.removeClass("notavailablecss");

                            Email.addClass("availablecss");

                            msgbox.html('<img src="Images/a.png"> <font color="Green"> Available </font>');

                        }
                        else {
                            Email.removeClass("availablecss");

                            Email.addClass("notavailablecss");

                            msgbox.html(msg.d);

                        }
                    }
                });
            }
            else {

                Email.addClass("notavailablecss");

                msgbox.html('<font color="#cc0000">Email must be unique</font>');

            }

        });

    });

 [System.Web.Services.WebMethod]

protected void txtPassword_TextChanged(object sender, EventArgs e, string args)
    {
 string returnValue = string.Empty;

 SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["ConnectionString"]);


try
{

SqlCommand sqlCmd = new SqlCommand("usp_CheckEmail", con);

sqlCmd.CommandType = CommandType.StoredProcedure;

sqlCmd.Parameters.AddWithValue("@Email", args.Trim());

con.Open();

int success = int.Parse((sqlCmd.ExecuteScalar().ToString()));

if(success == 1) // Email Not Available
{
returnValue = "<img src="Images1/n.png"><font color="#cc0000"><b>'" + args + "'</b> is    already in use.</font>";   **//getting syntax error here**

  }
  else if(success == 0)//Email is available
{
 returnValue = "Available";
 }

}
 catch
 {
 //Handle Error
 }
 finally
 {
 con.Close();
 }

return returnValue;
 }

    }
 }