function set_cookie ( cookie_name, cookie_value,lifespan_in_days, valid_domain )
{
    
    //var domain_string = valid_domain ? ("; domain=" + valid_domain) : '' ;
    document.cookie = cookie_name +"=" + encodeURIComponent( cookie_value ) +"; max-age=" + 60 * 60 *24 * lifespan_in_days +"; path=" + valid_domain ;
	// alert(document.cookie);
}

function get_cookie ( cookie_name )
{
   
    var cookie_string = document.cookie ;
    if (cookie_string.length != 0) {
        //var cookie_value = cookie_string.match ('' +cookie_name +'=([^;]*)' );
		var cookie_value = cookie_string.split(";");
		var resultCookie = ""
		for(var i = 0 ; i <cookie_value.length;i++){
			var verifyCookie = cookie_value[i].split("=")
			verifyCookie[0] = verifyCookie[0].replace(/^\s+|\s+$/g,"");
			if(verifyCookie[0]==cookie_name) resultCookie= verifyCookie[1].replace(/^\s+|\s+$/g,"");
		}
		
		return resultCookie;
    }
    return '' ;
}

function delete_cookie ( cookie_name, valid_domain )
{
   
   // var domain_string = valid_domain ?("; domain=" + valid_domain) : '' ;
    document.cookie = cookie_name +"=; max-age=0; path=" + valid_domain ;
}