Display Loading image animation while loading data from server asynchronously using javascript/jquery

 function AjaxCalltoGetResults() {  
   var xmlhttp;  
   var demoval="demo";  
   var responsestring;  
   displayloader("#myLoader"); // < -- Display Loading Animation   
   if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari  
     xmlhttp = new XMLHttpRequest();  
   }  
   else {// code for IE6, IE5  
     xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");  
   }  
   xmlhttp.onreadystatechange = function () {  
     if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {  
       responsestring = xmlhttp.responseText;  
       hideloader("#myLoader");// < -- Hide Loading Animation   
       DemoMethod(responsestring); // < -- Call Any Method or display Results   
     }  
   }  
   xmlhttp.open("GET", "Demopage.aspx?demovar=" + demoval, true);  
   xmlhttp.send();  
 }  
  //pass loader id to display/hide loader  
     function displayloader(loaderid) {  
       $(loaderid).css({  
         height: $(loaderid).parent().height(),  
         width: $(loaderid).parent().width()  
       });  
       $(loaderid).show();  
     }  
     function hideloader(loaderid) {  
       $(loaderid).hide();  
     }  

 //css for image display  
 .ajax-loader {  
   cursor: wait;  
   background:#ffffff url('../img/ajax-loader.gif') no-repeat center center;  
   -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=75)";  
   filter: alpha(opacity=75);  
   opacity: 0.75;  
   position: absolute;  
   z-index: 10000;  
   display: none;  
 }  

 //put this where you want to display image  
 <div id="myLoader" class="ajax-loader"></div>  

//Image

Remove SQL Injected Data from Data Column using asp.net c#

 using System;  
 using System.Data;  
 using System.Data.SqlClient;  
 public partial class Check : System.Web.UI.Page  
 {  
   SqlConnection con = new SqlConnection();  
   DataSet ds = new DataSet();  
   SqlDataAdapter adapt;  
   protected void Page_Load(object sender, EventArgs e)  
   {  
     retrievedata("tbltablename", "clmcolumnname");  
     remove("tbltablename", "clmcolumnname");  
   }  
   protected void retrievedata(string tablename, string columnname)  
   {  
     con.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["myconn"].ConnectionString;  
     con.Open();  
     string squery = " Select " + columnname + " from " + tablename;  
     adapt = new SqlDataAdapter(squery, con);  
     adapt.Fill(ds);  
     con.Close();  
   }  
   protected void remove(string tablename, string columnname)  
   {  
     using (SqlConnection connection = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["myconn"].ConnectionString))  
     {  
       int colcount = ds.Tables[0].Rows.Count;  
       int j = 0;  
       while (colcount > 0)  
       {  
         string injecteddata= Convert.ToString(ds.Tables[0].Rows[j][0]);  
         if (!injecteddata.IndexOf('<') < 0)  
          {  
           string datapart= "";  
           if (injecteddata.IndexOf('<') > 0)  
           {  
              datapart = injecteddata.Substring(0, injecteddata.IndexOf('<'));  
           }  
           string newqry = "UPDATE " + tablename + " SET " + columnname + "= @datapart WHERE " + columnname + " = @injecteddata";  
           SqlCommand command = new SqlCommand(newqry, connection);  
           command.Parameters.Add("@datapart", SqlDbType.VarChar);  
           command.Parameters["@datapart"].Value = datapart;  
           command.Parameters.Add("@injecteddata", SqlDbType.VarChar);  
           command.Parameters["@injecteddata"].Value = injecteddata;  
           try  
           {  
             connection.Open();  
             Int32 rowsAffected = command.ExecuteNonQuery();             
           }  
           catch (Exception ex)  
           {  
             Console.WriteLine(ex.Message);              
           }  
           finally  
               {  
                 connection.Close();  
               }  
         }  
         j++;  
         colcount--;  
       }  
     }  
   }  
 }