javascript - WebSQL Doing Strange things when adapting code -

i have adapted code try create multiple columns in websql database. seems create tables, not insert when told to. changed code number or columns create , insert (i think). can me diagnose why won't insert

    <script> //test browser compatibility if (window.opendatabase) {     //create database parameters 1. database name 2.version number 3. description 4. size of database (in bytes) 1024 x 1024 = 1mb     var mydb = opendatabase("cars_db", "0.1", "a database of cars like", 1024 * 1024);      //create cars table using sql database using transaction     mydb.transaction(function (t) {         t.executesql("create table if not exists cars (id integer primary key asc, item1 text, chair text, table text)");     });    } else {     alert("websql not supported browser!"); }  //function output list of cars in database  function updatecarlist(transaction, results) {     //initialise listitems variable     var listitems = "";     //get car list holder ul     var listholder = document.getelementbyid("receipt");      //clear cars list ul     listholder.innerhtml = "";      var i;     //iterate through results     (i = 0; < results.rows.length; i++) {         //get current row         var row = results.rows.item(i);          listholder.innerhtml += "<li>" + row.item1 + " - " + row.chair + " (<a href='javascript:void(0);' onclick='deletecar(" + row.id + ");'>delete car</a>)";     }  }  //function list of cars database  function outputcars() {     //check ensure mydb object has been created     if (mydb) {         //get cars database select statement, set outputcarlist callback function executesql command         mydb.transaction(function (t) {             t.executesql("select * cars", [], updatecarlist);         });     } else {         alert("db not found, browser not support web sql!");     } }  //function add car database  function addcar() {     //check ensure mydb object has been created     if (mydb) {         //get values of make , model text inputs         var item1 = "hamburger";         var chair = "cheese";         var table = "123";          //test ensure user has entered both make , model         if (item1 !== "" && chair !== "") {             //insert user entered details cars table, note use of ? placeholder, these replaced data passed in array second parameter             mydb.transaction(function (t) {                 t.executesql("insert cars (item1, chair, table) values (?,?,?)", [item1, chair, table]);                 outputcars();             });         } else {             alert("you must enter make , model!");         }     } else {         alert("db not found, browser not support web sql!");     } }   //function remove car database, passed row id it's parameter  function deletecar(id) {     //check ensure mydb object has been created     if (mydb) {         //get cars database select statement, set outputcarlist callback function executesql command         mydb.transaction(function (t) {             t.executesql("delete cars id=?", [id], outputcars);         });     } else {         alert("db not found, browser not support web sql!");     } }  outputcars(); </script> 

here code adapted (this 1 works fine!)

//test browser compatibility if (window.opendatabase) {     //create database parameters 1. database name 2.version number 3. description 4. size of database (in bytes) 1024 x 1024 = 1mb     var mydb = opendatabase("cars_db", "0.1", "a database of cars like", 1024 * 1024);      //create cars table using sql database using transaction     mydb.transaction(function (t) {         t.executesql("create table if not exists cars (id integer primary key asc, make text, model text)");     });    } else {     alert("websql not supported browser!"); }  //function output list of cars in database  function updatecarlist(transaction, results) {     //initialise listitems variable     var listitems = "";     //get car list holder ul     var listholder = document.getelementbyid("carlist");      //clear cars list ul     listholder.innerhtml = "";      var i;     //iterate through results     (i = 0; < results.rows.length; i++) {         //get current row         var row = results.rows.item(i);          listholder.innerhtml += "<li>" + row.make + " - " + row.model + " (<a href='javascript:void(0);' onclick='deletecar(" + row.id + ");'>delete car</a>)";     }  }  //function list of cars database  function outputcars() {     //check ensure mydb object has been created     if (mydb) {         //get cars database select statement, set outputcarlist callback function executesql command         mydb.transaction(function (t) {             t.executesql("select * cars", [], updatecarlist);         });     } else {         alert("db not found, browser not support web sql!");     } }  //function add car database  function addcar() {     //check ensure mydb object has been created     if (mydb) {         //get values of make , model text inputs         var make = document.getelementbyid("carmake").value;         var model = document.getelementbyid("carmodel").value;          //test ensure user has entered both make , model         if (make !== "" && model !== "") {             //insert user entered details cars table, note use of ? placeholder, these replaced data passed in array second parameter             mydb.transaction(function (t) {                 t.executesql("insert cars (make, model) values (?, ?)", [make, model]);                 outputcars();             });         } else {             alert("you must enter make , model!");         }     } else {         alert("db not found, browser not support web sql!");     } }   //function remove car database, passed row id it's parameter  function deletecar(id) {     //check ensure mydb object has been created     if (mydb) {         //get cars database select statement, set outputcarlist callback function executesql command         mydb.transaction(function (t) {             t.executesql("delete cars id=?", [id], outputcars);         });     } else {         alert("db not found, browser not support web sql!");     } }  outputcars(); 

if modify make/model part specific value rather getting input, works fine...its after try adding more columns.