function  chack_login(){

            var ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>';
            var loader_image = '<img src="<?php echo WP_iv_membership_URLPATH. 'admin/files/images/loader.gif'; ?>"/>';
                jQuery('#error_message').html(loader_image);
                var search_params={
                    "action"  :     "iv_membership_check_login",
                    "form_data":    jQuery("#login_form").serialize(),
                };
                var username = jQuery('#username').val();
                var password = jQuery('#password').val();
                if( password!="" && username!=""){
                jQuery.ajax({
                    url : ajaxurl,
                    dataType : "json",
                    type : "post",
                    data : search_params,
                    success : function(response){
                        if(response.code=='success'){
                            // redirect
                            window.location.href = response.msg;
                        }else{
                            jQuery('#error_message').html('<div class="alert alert-info alert-dismissable"><a class="panel-close close" data-dismiss="alert">x</a><?php  _e('Invalid Username & Password','wpmembership');?></div>' );
                        }


                    }
                });
            }else{
                jQuery('#error_message').html('<div class="alert alert-info alert-dismissable"><a class="panel-close close" data-dismiss="alert">x</a><?php  _e('Enter Username & Password','wpmembership');?></div>' );
            }
    }