In .NET environment there are situations where you want to call the code behind method of your application from the design page so in that case the name of the function to be called is passed into the script.

After doing this we will put that into a client side javascript or JQuery function which will invoke the function and the code behind function gets invoked.

 public string ConvertDataTabletoString()
    {
        DataTable dt = new DataTable();
        using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["DBConnectionString"].ConnectionString))
        {
            using (SqlCommand cmd = new SqlCommand("select title=Company,lat=latitude,lng=longitude,image from MapDimension", con))
            {
                con.Open();
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                da.Fill(dt);
                System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
                List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
                Dictionary<string, object> row;
                foreach (DataRow dr in dt.Rows)
                {
                    row = new Dictionary<string, object>();
                    foreach (DataColumn col in dt.Columns)
                    {
                        row.Add(col.ColumnName, dr[col]);
                    }
                    rows.Add(row);
                }
                return serializer.Serialize(rows);
            }
        }

This is the funciton which we want to call from the script end.

<script type="text/javascript">
    function initialize() {
        var markers = JSON.parse('<%=ConvertDataTabletoString() %>');
        var mapOptions = {
        center: new google.maps.LatLng(markers[0].lat, markers[0].lng),
zoom: 5,
mapTypeId: google.maps.MapTypeId.ROADMAP
//  marker:true
};

</script>