unexpected behaviour while inserting into database, phonegap sqliteplugin - jquery-mobile

Question

I have written a method to first display the contents of database as listview and upon clicking on the listview i will display a popup to enter the student name.
Upon entering the student name i will check in the database whether the name exists, if name exists i will alert saying name already exists else i will write the date into database
$('#storedList').children('li').off('click').on('click', function () {
name = $.trim($(this).text());
$("#existing_Name").popup('open');
$('#exisitng_Namebutton').on('click', function(e) {
var existname = document.getElementById('existingname');
createname = $.trim(existname.value);
//});
if(createname.length!=0){
db.transaction(function(tx){
tx.executeSql('SELECT * FROM SCHOOL WHERE Std_name="' + name + '" and CreatedDate="'+createname+'" ', [] ,CheckingAllignSuccess,errorCB);
});
}
else{
alert("please enter the value");
}
});
});
}
}
function Insertdbexisiting(tx) {
tx.executeSql('INSERT INTO SCHOOL (Std_name, CreatedDate) VALUES ("' + name + '","' + createname + '")');
}
function successCBexisting(){
Displaylist();
//window.open("list.html#Homelist");
$.mobile.changePage( "#Homelist", {
transition: "slide",
reverse: false,
});
}
var CheckingAllignSuccess = function(tx, resultallign){
if(resultallign.rows.length == 0){
db.transaction(Insertdbexisiting, errorCB, successCBexisting);
}else
alert("Student name already exists");
}
This works fine while adding the first value.
while adding the second value even though the second value is not present i get an alert message saying "Student name already exists".
when i debugged i noticed db.transaction(function(tx){
tx.executeSql('SELECT * FROM SCHOOL WHERE Std_name="' + name + '" and CreatedDate="'+createname+'" ', [] ,CheckingAllignSuccess,errorCB);
}); is calling 2 times if i am inserting data for 2nd time. it calls 3 times if i am inserting data for 3rd time
what is the mistake i am doing?. how will i prevent it?
Thanks:)

Answer 1

I fixed by adding off('click') to $('#exisitng_Namebutton').on('click', function(e) { i just made it has $('#exisitng_Namebutton').off('click').on('click', function(e) { and it is working fine.
This idea was suggested by Gajotres in one of his answers in SO.