javascript - generic ajax form submission -

ajax/javascript problem: have app consist of multiple forms. want achieve make generic js function submit forms respective controllers getting form id.. m getting form ids in form_id variable m unable use them. tried replacing $('patient_form') form _id , got following error: typeerror: form_id.on not function

here following code better understanding of problem:

$(function () {     var form = document.getelementsbytagname("form");     var form_id = "'#" + form[0].id + "'";      form_id.on('submit', function (e) {          e.preventdefault();          $.ajax({             type: 'post',             url: 'controllers/c_insertpatient.php',             data: $('#patient_form').serialize(),             success: function (result) {                 alert(result);             }         });      });  }); 

in addition other answers, want keep form id dynamic, right, can insert whatever values want?

$(function () {     var form = document.getelementsbytagname("form");     // note have convert jquery object     var form_id = $("#" + form[i].id); // i, can put in id form      form_id.on('submit', function (e) {          e.preventdefault();          $.ajax({             type: 'post',             url: 'controllers/c_insertpatient.php',             data: $(this).serialize(), // again, keep generic applies form             success: function (result) {                 alert(result);             }         });        });  });